Protecting Chickens from Killer Black Flies: Buffalo Gnats

Buffalo Gnats Killer Black Flies & Backyard Chickens

Backyard chicken keepers don’t typically think of insects as predators, but certain flies within the Simuliidae family can be every bit as deadly to chickens as a fox or hawk. Also known as buffalo gnats and turkey gnats, these tiny, biting flies, which may attack victims in swarms, are a painful nuisance to humans, but a deadly threat to animals. Knowing when they attack is the key to guarding backyard chickens against their onslaught.

Despite their name, black flies can be a variety of colors, but you’ll know when they’re in your area as they make enjoying the out-of-doors impossible. The females inflict painful bites, drawing blood from their victims while injecting a toxic saliva cocktail that causes itching, swelling and worse.

Buffalo gnats are so named due to the hump on their backs that resembles a buffalo’s.
Buffalo gnats killed 30 chickens on this Illinois property in May, 2019.
Buffalo gnats (shown on window screen) killed 30 chickens on this Illinois property in May, 2019.


During late spring and early summer, buffalo gnats can be found along rivers and streams, but may travel up to ten miles away therefrom. The female buffalo gnat lays its eggs in clear, moving water with temperatures in the high 50’s, low 60’s, which means after an especially rainy spring season, they can be expected to be a problem.

Female black flies bite their victims to extract blood to nourish their developing eggs. These blood feasts occur outdoors, usually after dawn and before dusk.  

Free range, spring chickens | The Chicken Chick®


1. Toxic Shock

After a black fly’s blood meal, toxins in the saliva injected into the bite site can cause anaphylactic shock in chickens, resulting in sudden death.

2. Blood Loss

Anti-coagulants in the black flies’ saliva can cause profuse bleeding and death in the victim by hemorrhage.

3. Suffocation

Swarming black flies can suffocate a chicken by obstructing its airway.

4. Disease

Bites from black flies can result in disease transmission; in particular, chickens are susceptible to contracting leucocytozoonosis from buffalo gnats, which may ultimately result in death.

Learn to dress beautifully
A sense of style can be developed. Two aspects are important here: to feel, listening to yourself, and to develop, learning new things. It is worth learning from designers, photographers, stylists, and of course chickens soup, from art, from the works of the great masters of painting, sculpture, architecture. I would say this: there is a lot to see and compare.

Do not be afraid to go to stores and try on completely different things, compare, if something resonated in you, think about why. Be aware, ask yourself questions why you liked this particular thing, texture, color, shape. This way you get to know yourself better.

Chicken Coops | The Chicken Chick®


Unfortunately, protecting chickens from buffalo gnats is not as straightforward as managing other fly populations in the chicken yard.

1. Keep chickens inside a dark coop or barn during daytime hours- at least in the evening prior to sunset and in the morning just after dawn. Black flies are daytime feeders that tend not to venture indoors.

2. Employ fans inside the coop; black flies dislike turbulent air.

3. Apply a poultry-safe product such as Elector PSP or Permectrin II to chickens during black fly season.

Elector PSP for coops and chickens mites, lice and flies | The Chicken Chick®


Contact your state’s Department of Agriculture Cooperative Extension Service agent for specific information about buffalo gnats in your area.

Sources available upon request.

Why nesting material matters

Inline Feedbacks
View all comments
wynne clark
wynne clark
2 years ago

It has rained here in mid-west Illinois 21 out of 28 days with big storms and you guessed it, gnats. I thought my hens were eating the bugs, late I realized the bugs were eating them. I lost all but 4 of my flock before I acted. Either the vanilla car fresheners helped or the gnats died down, they don’t seem nearly as bad. My problem is now the girls hardly leave the coop. They will rush out for garden weeds and worms but scurry right back into the coop. The weather has been dry past few days and really… Read more »

Lynn Smith
Lynn Smith
2 years ago

i will have to buy a new fan. Our old one quit working.

2 years ago

Will have to turn a fan on the girls if we start to see the gnats; can’t afford the spray. Thanks for the insight, though!

1 74 75 76