Flystrike can kill a chicken in as little as 48 hours. In one documented case, maggots consumed all the flesh of a young bird within that timeframe. The speed depends on how quickly the infestation is discovered, where on the body it starts, and how warm the weather is, but this is always a medical emergency measured in hours, not days.
How Flystrike Progresses So Quickly
Flystrike, also called myiasis, begins when flies lay eggs directly on a chicken’s skin, typically in areas that are moist, dirty, or wounded. Blowfly eggs hatch in roughly 12 hours. Once they do, the larvae immediately begin feeding on the bird’s living tissue.
That 12-hour hatching window is why flystrike accelerates so fast. By the time you notice something is wrong, the maggots may already be burrowing into the skin. As larvae feed, they release enzymes that break down tissue and create open wounds, which attract even more flies to lay additional eggs. This cycle can spiral within a single day. The tissue destruction leads to overwhelming infection and toxic shock as bacteria flood the bloodstream through damaged skin. A chicken that seemed fine in the morning can be in critical condition by the next evening.
Where It Starts on the Body
Flies are drawn to moisture and odor, so the vent area (under the tail) is the most common site for flystrike in chickens. Hens with loose droppings, “pasty butt,” or dirty feathers around the vent are especially vulnerable. Open wounds from pecking injuries, bumblefoot sores, or prolapsed vents also serve as landing sites. Any spot where the skin stays damp and bacteria are already present gives flies exactly what they’re looking for.
Because the vent area is hidden under feathers, infestations here often go unnoticed until they’re advanced. This is part of what makes flystrike so dangerous in backyard flocks: it can be well underway before you see any external sign.
Early Warning Signs
A chicken with flystrike will often become lethargic and separate from the rest of the flock. You might notice restlessness, a hunched posture, or a sudden loss of appetite. Some birds repeatedly peck at or shake the affected area. A foul smell coming from the bird is a strong indicator, as is any visible cluster of small white or yellowish eggs on the feathers or skin. By the time you can see maggots actively moving in the tissue, the infestation is already serious.
Daily inspections during warm months are the single most effective way to catch flystrike early enough to intervene. Pick up each bird and check the vent area, under the wings, and around any existing wounds.
What to Do If You Find It
Speed matters more than perfection. Your immediate goal is to remove every maggot you can see and clean the wound. Warm water baths help loosen maggots and wash them away from the affected tissue. One backyard flock keeper reported bathing her affected hen four times in a single evening to get the area clean. After removal, spray the wound with an antibacterial spray designed for poultry.
Isolate the bird in a clean, dry, fly-free space. Recovery from flystrike is slow even when caught in time. Expect 4 to 6 weeks of daily wound care, including re-spraying with antibacterial treatment, checking for any missed or newly hatched maggots, and keeping the area dry. If the tissue damage is extensive or the bird is in shock, humane euthanasia may be the kindest option.
Conditions That Increase Risk
Warm, calm weather creates peak flystrike conditions. The flies responsible become active when temperatures climb above 15°C (59°F) and are most active between 26°C and 36°C (roughly 79°F to 97°F). Humidity and recent rainfall make things worse because they keep feathers and skin damp, which is exactly what attracts egg-laying flies.
Summer and early fall are the highest-risk seasons for most backyard flocks, but any stretch of warm, muggy weather can create the right conditions, even in spring.
Prevention That Actually Works
Flystrike prevention comes down to keeping your birds clean and dry, and keeping flies away from the coop.
- Check vents regularly. Trim feathers around the vent if they become matted or dirty. Address diarrhea promptly, since loose droppings create the moist, odorous conditions flies seek out.
- Clean the coop frequently. Remove droppings and soiled bedding before they accumulate. Use dry, absorbent bedding like straw or wood shavings, and make sure the coop has good ventilation to reduce dampness.
- Control flies around the coop. Fly traps placed near (not inside) the coop help reduce the local fly population. Diatomaceous earth and poultry-safe essential oils can serve as natural deterrents.
- Treat wounds immediately. Any open wound, pecking injury, or prolapse should be cleaned and the bird isolated until it heals. An untreated wound in warm weather is an open invitation for flystrike.
The 48-hour window from egg to death is a worst-case scenario, but it’s not rare. Flystrike doesn’t give you much margin for error. Twice-daily checks during peak fly season take less than five minutes per bird and are the difference between catching an infestation at the egg stage and finding it after irreversible damage.