By Ken Johnson
Buffalo gnats are so named because of the hump on their backs.
If you’ve spent much time outdoors recently, there’s a chance you’ve had an encounter with buffalo gnats or eye gnats.
Eye gnats live in decaying organic matter as larvae. Adults are black and about 1/16-inch-long flies. While they don’t feed on blood they are can be quite annoying. They will feed on secretions of the eyes and noses of people and other mammals.
Buffalo gnats, which are also known as black flies, are small, 1/16- to 1/8-inch-long, humpbacked black flies. Females will bite and feed on blood in order to produce eggs (like mosquitoes). These bites can be painful and can cause bleeding, itching, inflammation and swelling, as well as allergic reactions in some people. Buffalo gnats have been known to kill poultry and other birds when their populations get high. The toxins from their bites can kill the birds or they can be so numerous they can suffocate them. They will also feed on the thinly haired areas of dogs, cats, and horses, such as ears and undersides. There are a several species of black flies that can be found in Illinois, and some can be relatively specific to host (they may only feed on a few types of animals). Because of this, some animals may be attacked more than others. Buffalo gnats are aquatic as larvae. They will live in clear, fast moving water. Since our waterways have been becoming cleaner the last few decades, we have seen an increase in their populations.
Adult buffalo gnats can fly up to 15 miles in search of a meal, but are most commonly encountered close to the water sources where they develop (usually around half a mile). Buffalo gnats are attracted to the carbon dioxide exhaled by people and animals and to perspiration, fragrances, and dark moving objects. They are most active on calm days, just after sunrise and just before sunset. Adults are typically active for 3 to 4 weeks.
Avoiding infested areas, especially when they are most active, is the best way to prevent bites. Like mosquitoes, they aren’t particularly strong fliers, so using fans while outdoors can help reduce bites.
Although many believe DEET-containing insect repellents are not effective, studies have shown that DEET repellents provide the most effective protection. Many have reported that vanilla can be a fairly effective repellent. Fortunately buffalo gnats won’t bite through clothing like mosquitoes, so only exposed skin will be attacked.