Swarm of gnats in Eastern Iowa redefining 'in your face'

Reports of fatal 'eye gnat' attacks seen among chickens

Buffalo gnats pose a particular danger to chickens. (Courtesy: Entomology & Plant Pathology Oklahoma State University)
Buffalo gnats pose a particular danger to chickens. (Courtesy: Entomology & Plant Pathology Oklahoma State University)

The swarms of gnats now hovering around your head, exploring your cranial orifices and redefining the expression “in your face” are often called “eye gnats” because they are attracted to the lachrymal fluids that keep your eyeballs lubricated.

The only good thing about them is they don’t bite, which distinguishes them from the buffalo gnats, also called black flies, that terrorized and in some cases killed warm-blooded animals in late May and early June.

Iowa State University entomologist Ken Holscher said eye gnats develop in moist soil, which has been plentiful in this year of record spring rainfall.

“They are capable of several generations each year,” he said, which means we likely won’t soon see the last of them.

We have seen the last of the buffalo gnats, which reproduce just one generation per year, Holscher said.

“They all come out at the same time, stick around for two to three weeks, and they are all gone at the same time,” he said.

The bite of the buffalo gnat, he said, often produces in humans swelling and itching worse than a mosquito bite, and it can prove fatal for birds and especially chickens.

“This has not been an especially bad year for poultry losses, but we’ve had several reports,” he said.

Joia Eales, who raises more than 100 chickens on a rural Linn County acreage, said she lost seven pullets and a laying hen this spring to the buffalo gnats. The pests killed all but two of a friend’s 67 broilers in just two days, she said.

Holscher said the saliva injected by the biting female gnat can cause fatal anaphylactic shock in chickens. They also can smother themselves when they pile atop each other to escape the biting gnats, he said.

Buffalo gnats tend to attack humans around the head. “They are attracted to carbon dioxide, which is more concentrated where we exhale,” he said.

They tend to bite in the tender spots around eyes and ears,” he said.Vanilla extract, dryer sheets and Absorbine Junior are often recommended to repel gnats, but Hoscher said nothing works very well.

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