How the Enemy Works...

Fleas

The hibernating cocoon
can survive
up to a year without feeding,
awaiting
optimal conditions

Adults can live
 up to 2 months without a meal
and can survive
7 to 8 months
with just one meal

 
There are more than 3,000 different species of flea, the most common being Ctenocephalides felis, (the cat flea), also the most common
on dogs. 

Fleas are similar to cockroaches in that they adapt to their environment: they become stronger and more immune to popular commercial flea control chemicals with each generation.  Moreover, an effective solution must also deal with eggs and larvae that come to life long after adult bugs are dead.  In truth, most of the fleas are living in the dog’s environment, rather than on his body: every flea found in his fur may mean that there approximately 30 more living in your home.

Fleas are holometabolous: which refers to their complete metamorphosis or change.  A flea's life span goes through four stages tied to external conditions, and the adult fleas that bite represent only the top, about 5% of the “flea population pyramid” total. 

The broad base of the pyramid—50% of the total population—is the vast number of eggs.  A female flea can lay up to 60 eggs each day (up to 900 in her lifetime).  But before doing so, she must find a “blood meal.”

Possessing little eyesight, she relies primarily on air currents and carbon dioxide to locate hosts: as your dog passes by, the persistent flea jumps up and down, sometimes thousands of times, before it hitches a ride. 

Once on board, the flea secretes saliva onto the target area to soften the skin and make the blood flow readily; it is this saliva (not the actual bite) that causes the allergic reactions in pets and humans.  After her blood meal, the flea begins laying eggs on your dog: some are removed as he grooms himself; others fall off as he moves about the house.

In 2 to 12 days the eggs hatch into wormlike larvae, (about 35% of the total population), which emerge from the eggs and feed on debris and organic matter in carpets, soil, or in cracks and baseboards.  The larval stage generally lasts 1 to 3 weeks, but under unfavorable conditions (80 – 90 degrees F. and humidity of 70% or more) it can last up to 200 days, before the larvae spin a cocoon and transform into pupae
(10% of the total). 

The hibernating cocoon is adaptive and can survive up to year without feeding, awaiting proper conditions (and detection of a host’s vibrations) to hatch and immediately seek a blood meal, thus begining a new generation.  Adults can live 1 to 2 months without a meal and can survive 7 to 8 months with just one meal.

The wide fluctuation in duration of the various stages accounts for the sudden emergence of massive numbers of fleas in what we know as “flea season”: they've been there all along, waiting for optimal temperature and humidity conditions to occur before maturing en masse.  The problem is that many common pesticides used to eradicate these pests kill only adult fleas, leaving almost the entirety of the flea problem behind to wreak havoc many times.
 
Statistically, efforts directed at the eggs and larvae will yield the best results, and prevent future generations from being born. 

Ticks are extraordinarily hardy, cannot be suffocated or drowned (they breathe only once every five hours), and are resistant to many chemicals.  Ticks belong to the class arachnida, which counts mites, spiders and scorpions among its members.  Infinitely patient creatures, ticks make their way onto the edges of leaves and branches, then stretch out their legs waiting to grab a ride on a passing “host,” from which they
take a “blood meal.” 

Sightless and deaf, the tick uses olfactory receptor neurons consisting of about 20 sensilla located on their first pair of legs (the Haller’s organ) that are narrowly tuned to the specific odor of butyric acid: a fatty smell emitted by warm-blooded creatures (also contained in sweat). 

The tick’s skin is photosensitive, and can detect warmth: it directs itself toward such heat, then drops from its perch onto the host (the dog).  As “obligate blood feeders,” ticks consume blood and as such, can transmit disease.  This most commonly happens when the tick first bores a hole (secreting an anesthetic, so it goes unnoticed), exuding a cementing material (to secure itself), and commencing its first meal.  Often the tick regurgitates a small amount of blood from its prior host, and it is in this way that the tick transmits disease, and to which pesticides cannot protect against (see previous page). 

A female tick will feed for several days, increasing as much as 200 times in weight before she's had her fill; once satiated, she falls to the ground where she lays thousands of eggs which emerge to re-start the cycle.  

Feeding for only a few days, the majority of the life of a tick is spent off the host in the environment either seeking a host, molting or simply passing through an inhospitable season (e.g., hot summers or cold winters).  Ticks that infest dogs include Dermacentor variabilis, the American dog tick; and Ixodes scapularis, the black-legged tick (erroneously nicknamed “deer tick” as a propaganda tool by advocates of recreational hunting).  They are known as three-host ticks: since at each stage of life (larva, nymph and adult) the tick feeds, drops off and transforms, then moves on to another host.

Controlling fleas and ticks on your dog necessitates ceaseless attention; it's never a onetime or occasional thing, particularly for a dog that may get walked in outdoor areas.  But why do some dogs seem to be infested with parasites… while others (even in the same household) aren’t?  The answer lies in nature’s plan, and the parasite’s role therein: to weed out and finish off unhealthy members of the various host species. 

The reason can often be found by comparing the general health of each animals' skin: the fastest-growing organ of its body, with the outer layer of cells being replaced every 3 weeks.  Optimum nutrition is essential for healthy skin; improperly nourished, the skin will be the first area to show problems.  Dry, unhealthy skin causes itching, as well as more severe reactions to fleabites, as the skin may bleed and actually “fall apart”; under these conditions, fleas need not chew to extract blood… and flock to this host.  A strong immune system and high nutrient levels help repel insects: many infestations can be avoided with an improved diet, augmented by an Omega-3 (fish or flaxseed oil) supplement.

Ticks

How does a tick "choose" a host
to feed on?

Synthetic vs. “Organic”:
What's the difference?

Pyrethrum sprays

Pyrethrums are natural (organic) pesticide found in a gene of certain species of chrysanthemum flowers. 

Central Asians discovered that the seed cases of dried, crushed flowers were toxic to insects centuries ago.  More recently, during the Napoleonic Wars (1804-1815) this “insect powder” was used to control flea and body lice infestations by French soldiers.

Permethrin insecticides

Permethrins are synthetic (laboratory made) chemicals based on analogs (chemical structures) of natural pyrethrums.  They are “artificial” by definition, because they are engineered: produced from chemical alteration.  Permethrins were first developed in 1942 and adapted for agriculture applications in 1973; and subsequently for pharmacy use to fight scabies (Sarcoptes scabiei skin mite) and (Pediculus humanus capitislice) head lice. 

Permethrins kill on contact when sprayed on clothing.  Unlike pyrethrums, permethrins maintain stability when exposed to sunlight and heat, and are used agriculturally on different crops. 

Permethrins are generally stronger and last longer.  However, as broad spectrum insecticides (they kill indiscriminately), they also harm beneficial insects, including honeybees and butterflies, and can be highly toxic to aquatic species (who cannot metabolize them) through their bioaccumulated persistence in the environment. 

Since the mid-2000s, research has focused on integrating an enzyme inhibitor to disable the insect’s resistance mechanism. Permethrins marketed with language intimating “made from chrysanthemum flowers” are falsely advertised.  Pesticide-grade permethrins are fatally toxic to cats.

Modern mixtures are of several different compounds of pyrethrins and oily esters called cinerins, which at low concentrations are effective as repellents.  Today, pyrethrum is extracted with solvents for insect sprays and typically combined with piperonyl butoxide (PBO: a synergist). 

Despite its efficacy as low toxicity insect control, pyrethrums are not stable in sunlight and thus are seldom used in commercial agriculture.  Pyrethrums are also toxic to honeybees, and so if so used for so-called “organic” farming, are applied at night to avoid typical pollinating hours, and in liquid rather than dust form.

Organic pesticides are generally less efficacious, in that they take longer to work, and do so for a
shorter duration.

Fish and aquatic invertebrates lack the ability to metabolize these compounds, leading to a toxic accumulation of byproducts if exposed from runoff or application drift.


 

Removing insects
is the most effective "Treatment"

Statistically, efforts directed at the eggs
and larvae
will yield
the best results,
and prevent future generations from
being born. 

Treatment of your home must begin with a thorough cleaning:  vacuuming picks up fleas and eggs from carpets, floors and crevices, and from under or on furniture.  Experiments done on nylon carpets have shown vacuuming provides the same level of control at the pupal stage as permethfin, a widely used
synthetic pesticide. 

Persistence is key, with frequent vacuuming of the house, (especially pet areas), paying careful attention to dark, damp places where fleas may have deposited eggs, as an important step to keep fleas from gaining a foothold.  A change in the house is necessary: abruptly banishing clutter, throw pillows, magazines, etc., speeds the process, which success depends on repetition.  Be willing to move and turn over furniture
for access.

Since larvae wrap themselves around the base of carpet fibers, and hang on, vacuuming may be only partially effective in removing the flea larvae in carpeting.  But vibration from vacuuming can result in the emergence of adult fleas from the pupal stage, and the newly hatched fleas may be removed prior to ever meeting your dog.  After vacuuming, the cleaner bag (or permanent cup, if a bagless unit) shouldn't be left in the machine: since the fleas may escape and the eggs it contains can hatch and re-infect your house: throw it out (or at least keep it outside between uses) or otherwise destroy the contents.  For severe infestations, a professional steam cleaning is in order.

Vacuuming is important since flea larvae feed on non-viable eggs and feces from active adult fleas.  In 6 – 14 days the larvae develop through three stages prior to spinning cocoons so that they may become pupae, (at which they simply await (perhaps for months) ideal conditions to emerge.  Larvae avoid sunlight, burrowing deep into carpeting and seeking dark crevices in floors or along baseboards.  Although larvae can survive a damp mopping (cocooned adults can survive immersion in water), its still useful, since water dissolves flea feces, and so deprives them of a food source.  Pre-emergent adult fleas will emerge if provoked, most particularly by detecting a worthy host to feed upon: and the heat and pressure within the dog’s bed (where they likely drop off the dog originally) triggers the process.

Often forgotten is the family vehicle: if the dog gets in, it should be vacuumed thoroughly and repeatedly.

Boric Acid

For carpeted areas, boric acid (hydrogen borate: nontoxic borate crystal salt) dissolves the waxy protective coating (exoskeleton) on fleas, eggs, and larvae, causing them to dessicate (dehydrate), effectively targets flea larvae on contact, yet has extremely low toxicity to dogs; (troublesome only if directly inhaled, or, around a dog with wounds from existing dermatitis).  Shake the product onto the carpet and work it in with a broom.  The extremely fine particulates can remain in the carpet, even after vacuuming. As its killing action is mechanical, not chemical, fleas cannot become immune to its effects. 

Note that “boric acid” is not the similarly sounding sodium polyborate powder (a commercial product), nor 20 Mule Team™ from the grocery store; neither the hand soap Boraxo®, (of which the added soap can be toxic to dogs).

HEAT/LIGHT
FLEA tRAPS 

Heat is indicative of a warm-blooded host, and will stimulate and attract fleas: you can suspend a bare bulb 6-12 inches over a pan of water with some dish soap added: surfactants in the soap reduce the water’s surface tension, causing the fleas to sink and drown.  However, the light itself is important: even though fleas will orient themselves toward heat, absent further stimuli, they will not jump to a host (or the trap).

DE, the fossilized
skeletal remains of diatoms remain effective as long as kept dry and undisturbed.

Diatomeceous Earth  

Once your home is sanitized, defend against a recurrence of fleas by applying small amounts of “food-grade” diatomaceous earth (DE) throughout.  Appearing similar to baby powder, diatomaceous earth is diminutive fossilized skeletal remains of diatoms: unicellular acquatic plants: a major group of algae, and a common type of phytoplankton.  The skeletons are made of a natural substance called silica.  Over a long period of time, diatoms accumulated in the sediment of rivers, streams, lakes, and oceans, and silica deposits are mined from these areas.

Silica is very common in nature and makes up 26% of the earth's crust by weight. Various forms of silica include sand, emerald, quartz, feldspar, mica, clay, asbestos, and glass. Silicon, a component of silica, does not exist naturally in its pure form, because it reacts with oxygen and water to form silicon dioxide.  Silicon dioxide has two naturally occurring forms: crystalline and amorphous; most commercially available diatomaceous earth is made of amorphous silicon dioxide, but can contain very low levels of crystalline silicon dioxide. The first pesticide products containing silicon dioxide (diatomaceous earth) were registered in 1960.

The microscopic, razor-sharp edged particles of DE attach and absorb oils and fats from the cuticle (the waxy protective outer coating) on the flea's exoskeleton, leading to dessication (dehydration) and death.

The most common formulation of diatomaceous earth is as a dust.  It only takes a small amount of DE a large area indoors if it is strategically placed near problem areas such as under the baseboard heaters, beneath the stove or cupboards, near the sink, garbage, etc.  Effective on carpeting, if sprinkled on bare wood floors DE will drop into cracks and crevices favored by fleas.  DE remains effective as long as it is kept dry and undisturbed; it can be accidentally sucked up when vacuuming, so reapplication may be necessary after ordinary cleaning.  Non-toxic, DE can also be rubbed directly into your dog’s fur.
 
You should continue application of diatomaceous earth after the resident flea population is exterminated, because hibernating fleas in the cocoon stage may survive in the home environment up to a year without food.  This stage can survive most chemical treatments and can emerge to reintroduce the flea population.

Diatomaceous earth for pest control should not be confused with “pool grade/pool filter grade” diatomaceous earth, which is treated with heat, causing the formerly amorphous silicon dioxide to assume crystalline form which is not effective for insect pest control, and can be toxic to dogs.

Non-thermal wet or dry fogging

For severe flea and tick infestations, or, in cases where de-cluttering is difficult, solutions include a low volume chemical-free fogger that uses a turbine to thrust an atomized solution of cedar oil and melted quartz rock (acting as a carrier) as a cold dry mist which can penetrate into cracks, behind furniture, through jumbled basements and clothes-filled closets, outside house perimeters and yard areas, etc.; and which is ideal for fumigating disorderly areas such as basements and attics, with a fog-drift of up to twenty feet.  

As such, cedar oil can be an ideal non-persistent fumigant for repeat applications, or for large-scale de-infestation projects (industrial applications, hotels, etc.), as an alternative to commonly used (but hazardous, and regulated) Bromomethane, (methyl bromide) pesticides.

A clove a day...

In many respects, the simplest and most effectie preventative will mask the specific odors on your pet that pests are searching for in the environment: if the formula is effective, fleas and ticks cannot smell, taste, or even identify the host they're seeking.  Many herbal or natural remedies can work just as well as chemical solutions. 

Many dogs seem to benefit from the addition of garlic and nutritional or unprocessed brewers yeast (Saccharomyces cerevisiae) to their diets. 

When metabolized, an odor (and bitter flavor) that fleas and ticks find very unattractive develops in the skin.  The odor betrays the allicin content in garlic, a phytochemical (a naturally occurring biologically-active enzyme, that is produced when the plant is attacked or injured) which is toxic to insects.  The important flea-control ingredient in brewer's yeast is thiamine (vitamin B1), which concentrates in the skin and can repel fleas.

MAGNETIC TAGS and collars

A mildly controversial “technology” offered against biting pests is magnetic tags that attach to a dog collar.  Sometimes worn in pairs (one each: for fleas and ticks) magnetic tags (silicon dioxide particles encoded with specific frequencies that are emitted over time) “synchronize” to the dog’s external bio-energetic field: proven to disturb fleas and ticks, creating a barrier.  This process takes several weeks to align and become effective. Although dismissed by many as wholly ineffective, the tags are used in agricultural environments and have enthusiastic advocates, and are backed by significant targeted research, claiming effectiveness for up to 2 years.  

Collars made from natural unpolished raw Baltic amber generate a slight static charge that “prevents insects from clinging onto your pet’s fur.”  The collars last until friction causes the beads to become polished, stated to be
about six months.

Established but disputed technologies include ultrasonic pendants that emit a series of ultrasonic (high frequency: more than 20,000 HZ) sound waves that are supposedly imperceptible to the dog, but which are intolerable to fleas and ticks, repelling them for the life of the battery: said to be about 12 months.  Consumers should expect validation: in 2001, the US Federal Trade Commission (FTC) sent a warning to manufacturers of ultrasonic pest control devices (at that time, indoor rodent targeting devices), demanding that claims of effectiveness be supported by scientific research, to avoid violations of federal consumer protection law.

Neem Oil

coconut oil

white vinegar solutions

citrus juice

A  vegetable oil pressed from the fruits and seeds of a tropical evergreen tree, neem oil is used as a bio-pesticide in organic farming and medicinal applications.   Pure neem oil can is commercially available as shampoo (alternatively, by adding neem oil to conventional shampoos), and used heavily diluted for topical flea repelling application; or as a paste, the oil is extracted from dried neem leaves for a variety of skin treatments.  Neem leaf is also administered orally to improve
general skin condition.

Still, studies found dose-related impairment of thyroid function and hepatotoxicity in animals: (Panda S and A Kar., How safe is neem extract with respect to thyroid function in male mice? Pharmacological Research, 2000;41(4):419-422).  It is also essential for awareness that not all “natural oil” remedies are safe.  Example: pennyroyal oil is often suggested as a flea remedy for domestic animals, despite being well documented for imparting serious hepatic and neurologic injury (nausea, vomiting, respiratory difficulty, gastrointestinal bleeding, seizures, and coma, followed by coagulation abnormalities, disseminated intravascular coagulation, massive hepatic necrosis, and death).
 

A skin rub can be made from a half-tablespoon of virgin, un-refined coconut oil diluted with water into a spray before setting out for a walk.  The oil contains lauric acid, a medium chain fatty acid found in “mother’s milk” that boosts the immune system against bacterial and viral infections.  It has known natural effectiveness as a flea, tick, and mite repellent, with the added benefit of skin and coat conditioning.  Coconut oil can also be ingested, by adding 1 teaspoon per 30 lbs. of body weight mixed into food, augmented by brewer’s yeast (as a repellent, but the oil has natural antifungal, antibacterial, and antiviral properties and helps expel or kill intestinal parasites).
 
A spray for misting the dog (or furniture and pet bedding) can be a white vinegar solution: 3 parts water/1 part white vinegar, with a few drops of tea tree oil.  Alternatives: Lemon, salt and vinegar spray; boil several lemons in water with a few tea spoons of salt.  Once cooled, add one table spoon of apple cider vinegar.  Spray it onto the dog’s coat and leave it to dry naturally.  Apple cider vinegar, salt and baking soda spray: 8oz. vinegar, 4oz. warm water, ½ tbs. salt, ½ tbs. baking soda (spray it onto the dog’s coat and leave it to dry naturally).

Unpasteurized apple cider vinegar (about a teaspoon added to his daily drinking water) supports the immune system, or, add two cups to his bath water.  
 
The juice from a freshly squeezed orange or lemon can be lightly rubbed onto your dog's fur to repel fleas.  Its important to note that citrus oil extracts are not safe for dogs, as the oil that is extracted from the rind of the citrus fruit contains limonene.  While limonene is indeed an effective insect repellent (and all-purpose household cleaner), it is also a skin irritant, and can cause liver damage if ingested.  However, the oil is specific to the cells within the rind of the fruit and can only be extracted using specialty equipment, and so is not found in the fresh-squeezed
juice of the fruit.

A newer natural agent, d-Limonene, is a by-product of the citrus industry (the rinds) and carries a mild, grapefruit-like odor.  It is used as a precursor to carvone, found in natural essential oils (oils extracted from plants), employed as a
mosquito repellent.

Quassia-based Botannicals

Quassia is a flora genus in the family Simaroubaceae. Its breadth is disputed; some botanists regard it as consisting of only one species, Quassia amara from tropical South America, while others use a wide circumscription as a pantropical genus containing up to 40 species of trees and shrubs. The genus was named after a former 18th century slave from Surinam, Graman Quassi, who discovered the medicinal properties of the bark of Quassia amara (also known as: Amargo, bitter ash, and bitter wood).

Amara extracts have shown effectiveness as a contact-insecticide (the insect must be sprayed) and antiparasitic.  Extracts of plant wood or bark have been known as a natural insecticide and larvacide in organic farming environments. A commercially prepared “herbal spray,” (which is rubbed into the skin to assure coverage), combines sispanga, sacha café, and sisopanga rojo.  It can last up to several weeks (depending on the dog’s activity).   An oral tick preventative that is added to the dog’s food is claimed to last 2-3 months after a 5-day dosing, and combines larrea mexicana, chapparel leaf aromatica, Oregon grape root quassia amara, quassia tansy, and thyme vulgarus.

Eucalyptus

Lavender

Peppermint



Rose Geranium Oil




geraniol




Palo santo



Palmarosa




clary sage


Patchouli

Lemongrass
cinnamon
wintergreen

The concentrated volatile essences (oil) steam distilled from leaves of the eucalyptus tree can augment bath water as a natural deodorizer and flea & tick repellent, incorporated into conventional shampoos, or misted onto his bedding. 

A light-scented oil steam distilled from the flowers of Lavandula officinalis.  Further to its medicinal benefits, lavender has a delicate and beautiful fragrance, known for its calming, anti-depressive, effects on dogs, and incorporated into shampoos or spray, can be used to repel fleas and ticks.

Steam distilled from the leaves and flower tops of the hybrid mentha piperita plant, repels fleas with a strong odor, used as a spray, wipe-on, or shampoo additive; and also for its high concentration of menthones (natural terpene pesticides:
see above).
 
Of the two varieties of rose geranium oil Pelargonium capitatum x radens.  The more popular oil under the name Pelargonium graveolens is from the same family, but not the same species.  If used in small doses, does not need to be diluted; dogs have such sensitive smell that they may be annoyed: one drop behind each shoulder blade and one drop on the tail has been described as an effective tick repellent, or rubbed into a bandanna that can be wrapped around the dog's neck.

A monoterpenoid, extracted from geraniums and lemongrass; a primary compound of rose oil, palmarosa oil, and java-type citronella oil.  An effective repellent, plants destined for commercial oil production are grown specifically for their higher concentration of oils and generally come from, Nepal and Southeast Asian countries.
 
Bursera graveolens (Spanish: palo santo, or “holy wood”), the essential oil of wild South American tree bark.  Users report success making an herbal flea/tick collar: 2 tablespoons almond oil with Rose Geranium Oil or Palo Santo, dabbing a few drops on the dog’s neck area (or directly on his collar).
 
Cymbopogon martini, (flea repellent) a grass of chemotypes or varieties, Motia & Sofia, of slightly differing aromas and which may be substituted depending on the demand of the market.  The essential oil is steam distilled before flowering.  The main constituents are geraniol, geranyl acetate, dipentene, linalool, limonene, and myrcene.  Smells like rose oil, and is often adulterated with it, since it is cheaper.
 
Salvia sclarea, oil steam distilled during flowering, a biennial or short-lived herbaceous perennial in the genus Salvia (flea repellent).

Steam-distilled dried leaves of Pogostemon cablin or Pogostemon patchouli, native to tropical regions of Asia, is often blended with oils of safe, geranium, lavender, as an effective and long-lasting repellent in sprays or shampoos.  A centuries-old ingredient in perfumes and incense, the sweet, minty order can be
irritating if overused.
 
Steam-distilled leaves of LEMONGRASS OIL, CINNAMON OIL and WINTERGREEN OIL formulated as a spray or wipe are well-known as effective repellents.  However, avoid any product blended with Pennyroyal Oil, since while effective—and often listed as a remedy for the purpose—has been shown to be highly toxic to dogs.

Essential oils should always be used diluted, even when just inhaling.  Careful dilution is essential: commercially available pre-diluted solutions offer a safer alternative for the amateur.  And diluting doesn't mean that they can be added to food or drinking water, since ingesting the oil can be toxic. 

PREDATORY NEMATODES

Nematodes are microscopic worms that eat flea larvae and are therefore a natural way to control flea populations.  They are available at pet and garden stores or online.  Using a lawn sprayer, (ideally after a rain has soaked the ground), put them in moist, shady spots near your house, and within 24 hours the resident flea population can be reduced up to 80% depending on area sprayed. 

As nematodes multiply rapidly, you have only to introduce a small initial number to have residual benefits (who last between 4 and 8 weeks individually). Flea control nematodes, however, are not uniformly effective in all outdoor environments; though research is inconclusive, evidence suggests that nematodes are most effective against fleas in moist, sandy soils (neither fleas nor nematodes survive in hot sun).  Cold winter weather will cause nematodes to become dormant and decline, (necessitating a re-introduction the following spring); and also, as a biological control need to be reintroduced periodically: because they eat all the prey species and die off for lack of food.

CRY FOWL

Free-range chickens, turkeys and particularly guineas are relentless insect eaters and will feed on ticks.  The Guinea Fowl International Association reports that 65 percent of its members have noticed radical declines in tick populations after they began keeping guineas; a single guinea can clear 2 acres in a year (see: Jeannette S. Ferguson; Gardening with Guineas).  Egyptian nobility regarded the guinea fowl as a prized
game food. Generally sold as chicks (keets), there are now more than 14,500 guinea farms in the U.S., fourth in fowl after chicken,
turkeys and ducks.