Summer Pests in Chickens
How many of you enjoy watching chickens take dust baths? They’re so cute when they flop around, contorting themselves and throwing dirt over their feathers.
But dust baths aren’t something chickens do to look adorable. Rather, they’re integral to a chicken’s instinctive pest-management strategy.
Some of the most dangerous enemies of chickens aren’t predators. Often the worst ones are the tiniest: gnats, fleas, lice, and mites. Here are some summer pests you should know about and what to do about them.
Pests can cause many symptoms among chickens: excessive preening, itching, weight loss, reduced egg-laying, broken or missing feathers, anemia, and in the most extreme cases, death. If your backyard ladies exhibit one or more of these signs, examine them and their environment for causes.
Addressing something as pernicious as pests often means breaking up the pest’s life cycle. This can include improved sanitation inside the coop, mechanical controls (such as fly strips or other traps — make sure they’re out of reach of chickens), and even biological controls (beneficial pest-eating insects). Monitoring and reducing moist environments is enormously important. For this reason, eliminate persistent damp spots (such as bedding under waterers) as much as possible, clean manure out regularly, and spread thin (to dehydrate).
Food-grade diatomaceous earth (DE) is one of the most helpful, universal, and affordable tools in the pest-treatment repertoire. This white powder is the fossilized remains of marine phytoplankton. (Make sure you use food-grade diatomaceous earth, not the material used to filter water in swimming pools! Swimming-pool DE is dangerous to human and animal health.) Diatomaceous earth works by abrading insects’ outer shells (cuticle), which causes death through dehydration. It is harmless to larger animals, except care must be taken (for both people and chickens) not to inhale it or get it in the eyes.
Purchase DE from most feed stores and in quantities from two to 50 pounds. A little goes a long way, so it’s probably best to start with a smaller bag and see how far it takes you.
For flies, sprinkle DE on the bare floor of the coop before layering down bedding. You can also rub it onto roosts and nesting boxes. This will not only dehydrate chicken droppings, but it will kill fly larvae.
Diatomaceous earth can serve as a lice treatment. (Be sure to wear mouth and eye protection during application.) While dusting the bird’s entire body is helpful, concentrate on dark, moist areas such as under the wings and on the vent. Try to get the DE on the base of the feathers since lice lay their eggs there. Avoid getting the DE near the bird’s head. Repeat this treatment once a week for three weeks to address eggs as they hatch. (As an alternative to diatomaceous earth, some people use wood ashes.)
Mites are another affliction for chickens but even harder to treat because they don’t live on the birds full-time. Instead, they creep out of cracks and crevices and feast on blood during the night. The trick to controlling mites is to make their lives as miserable as possible. Paint (or whitewash) the coop to fill in tiny cracks and crevices (the lighter color will also make it easier to spot these tiny arachnids). Use diatomaceous earth on surfaces — not just floors, but walls, perches, and nesting boxes.
Additionally, make sure your ladies have a place to take dust baths, even in winter. All that’s needed is a shallow, boxed-in area filled with equal parts dirt, sand, and diatomaceous earth (or wood ash). Dust baths suffocate insects on the skin and keep mites and lice at bay.
Herbal repellants can also relieve hens — strong-smelling sachets of eucalyptus, garlic, vanilla-soaked cotton balls, mint, rosemary, lavender, dill, basil, etc. You can also plant areas outside chicken yards and runs with lemongrass (or citronella), mint (keeping in mind mint will spread), basil, etc. Traps of water or vinegar (mixed with a bit of dish soap to break up surface tension) baited with meat, fish, or maple syrup will attract flies. (Keep traps out of reach of chickens.)
A Word on Buffalo Gnats
The tiny buffalo gnat (sometimes called black fly) deserves special mention. These nasty pieces of flying woe “attack like speedy, tiny, dive-bombing missiles,” in the words of Backyard Poultry writer Gina Stack. “[T]hese gnats … they are not just regular, annoying, everyday summer gnats. These are ferocious, blood-sucking, chicken killing, mini-predator machines.”
These micro-sized insects may be small but make no mistake: They’re killers. They’re attracted to carbon monoxide (when animals exhale), then swarm the animal. Their mouthparts are serrated, so they cut the skin and suck the resulting blood. They also inject an anticoagulant, often leading to anaphylactic shock. They bombard in such numbers that they can block respiratory tracts or cause panicked chickens to pile up on each other and smother. Birds can also bleed to death. In short, these are not pests to dismiss as insignificant.
You can combine citronella oil with a carrier oil (coconut oil, cocoa butter, mango butter) at one drop of citronella to one tablespoon carrier. Apply this mixture to the chickens’ wattles, combs, and other exposed membranes, keeping it away from the eyes.
Additional precautions include fans (gnats don’t like moving air), darkness (they prefer sunlight; even providing shade for the hens will help), and fine-mesh screening on the coop (or even creating a temporary mesh pen). Buffalo gnats are only active for about five weeks, so protective measures only have to be temporary.
For extreme control of buffalo gnats, you may need to resort to the bio-pesticide permethrin (derived from the chrysanthemum flower). To spray structures, use one ounce 13.3% permethrin mixed with one gallon of water, and spray the walls and floor of the coop (without any birds inside). Keep the door closed and the birds outside until the spray dries. At a lower concentration mixed with water, permethrin can also be applied directly (and cautiously) on the birds. Spraying permethrin onto a piece of cloth (such as a bandana) and hanging it in and around the coop may also help deter gnats.
However you choose to handle buffalo gnats, don’t assume your birds can handle things independently. Often they can’t. Don’t risk losing flock members to these nasty little biters.
Originally published in the June/July issue of Backyard Poultry and regularly vetted for accuracy.