Reading Time: 5 minutes
By Gina Stack
“Those gnats are back!” I yelled, startling our out of town guests while showing them our chickens on a warm, sunny day at the end of May in southwest Wisconsin.
The chickens were doing the characteristic jerking of their heads and twitching as if someone was poking them all over with sharp needles. The gnats were starting their attack like speedy, tiny dive-bombing missiles. I felt like announcing, “Incoming!” and running for some unseen shelter.
I tried to swallow down my panic, but my face probably looked as if I was going to get hit by a fastball coming in at 100 mph. My mind flew to all the protective tasks that needed to happen to protect my hens, but since it was the day before our son’s wedding, I knew I could do nothing except tell our neighbors tips to do, since they were taking care of the girls while we were gone for the weekend. Well, I thought, since I had just now noticed the gnats, maybe they won’t be too bad for a couple days. I had these gnats over the years and although annoying, irritating, and requiring a lot of extra care, we had gotten through, but I was still nervous.
I had three flocks of 20 chickens that we moved around in chicken tractors to protect from varmints. They are opened on nice days to let the sunshine in and the breeze through and closed up at night. This had worked for 12 years. Two pens had a mix of old and new hens. Nine-year-old Jan, talkative Thelma, big Louise, and a blend of others. One small pen had my favorite little Polish girls that look like they came out of a Dr. Seuss book. Most of them had names to go with their personalities like Goldie Hawn, Mrs. Gray, Mrs. Wiggins, and Gladys.
We were leaving that afternoon, so I warned our neighbors about the gnats and told them to stick a few dryer sheets into the chicken wire, as I had heard that helps (I guess it doesn’t), and off we went to enjoy the wedding. All seemed well and under control, or so I thought.
So, these gnats … they are not just regular, annoying, everyday summer gnats. These are ferocious, blood-sucking, chicken killing, mini predator machines! I had no clue that the gnat population had exploded beyond my control this particular year.
Another name for them is the buffalo gnat, because of its humpbacked appearance. They are also known as simply “black flies.” This seems too mild of a name. Maybe when Adam named them in the Garden of Eden, they were then just plain black flies. But when he and Eve ate from the wrong tree, they became vicious and changed to the merciless killers that they are. You must be prepared for these miniature enemies if you love your layer hens!
These flies are in the Simuliidae family of blood-sucking flies. There are about 30 species in Wisconsin. They are aquatic insects that prefer fast-running, clean water. The females lay hundreds of eggs near or in the water. The larvae hatch and feed on bacteria, then grow into pupae. When the adult black fly comes out of its cocoon, it crawls to the surface or floats up in a bubble of air, the bubble pops, and out flies the tiny terrorist. They are only 1/16th to 1/8th inch in size, so very small! They are usually where there are rapids in rivers or waterfalls, but adults will fly in search of blood 10 miles or more. There isn’t any water like that near us, so they zoomed over to our place.
Both males and females feed on nectar, but the males do not bite. A blood meal is required for females to produce eggs. With very small serrated mouthparts that act like scissors, they cut the skin and devour the blood. An anticoagulant is then injected, which after several bites makes animals go into shock when swarmed. This is called simuliotoxicosis, or acute toxemia and anaphylactic shock. Also, they will block the chickens’ respiratory tracts or they pile up on each other, causing them to smother.
How they attack is the males swarm the head, attracted to the carbon dioxide we and animals breathe out. Then the females execute their sneak assault on humans, chickens, cows, pigs, sheep, goats, dogs, and even deer. Also, songbirds and their nestlings! When they are abundant and swarm, they can kill any of the animals listed but especially chickens. They are most active at dawn and before sunset.
So, what can you do to prepare yourself if your area gets bombarded? To start, the gnats live for only about five weeks, from the end of May to mid-July in my area. They rarely come indoors and don’t like enclosures or moving air.
Here is a list of deterrents I compiled. I have not used them all, so please follow label directions and dilutions. You can use vanilla-soaked rags, fly strips by the windows that have very fine screening, and running fans in an enclosure. I like the fly strips because you can see results. I am going to do something like this combination. Also, citronella or geraniol oil spray, permethrin, Absorbine, diluted rubbing alcohol spray, VapoRub on towels, or ACV with dish soap. Things that don’t work are Deet, Sevin dust, dryer sheets, and garlic.
You can try mosquito traps or bug zappers that make a very satisfying sound when zapping. There are products that convert propane into carbon dioxide then draw the flies into a vacuum.
At the wedding, our poor neighbors started calling my husband during dinner when they found my chickens dead and dying. I had to keep a happy face and managed to get through all the festivities. Driving to the hotel, I sobbed, thinking all 20 chickens were dead. Thelma, Jan, Gladys, Mrs. Wiggins, my poor girls, my pets, all dead.
The next morning, we heard five were still alive and in the garage. We bolted in to see who made it! There was old Jan, loud Thelma and big Louise, an Easter Egger I eventually called Favor, and a quiet black chicken who became known as Mercy because of God’s favor and mercy on them.
The remaining 15 stricken hens lay lifeless in big, black garbage bags. I cried as I stood there, vowing vengeance on those gnats.
Gina Stack is a freelance writer in southwest Wisconsin. She, along with her husband and son, reside on five acres with 22 laying hens (some as old as ten years!), a large vegetable garden, perennials, and Lily the pug.
Originally published in Backyard Poultry August/September 2020 and regularly vetted for accuracy.
Buffalo gnat photo credit: D.Sikes (CC BY-SA2.0)