I like to jog. What I don’t like are those little gnats that sometimes fly up my nose or in my mouth and totally mess up my marathon-worthy rhythm. When a larger-sized fly goes up my nose, it’s almost impressive. I want to commend the fly by saying, “Of all the places for you to cram your chunky bug body, you manage to go up my narrow nostril? Well played, fly, well played.” But there is nothing impressive about gnats. They are just little, annoying twerps that swarm around in mindless circles like 13-year-old girls at the mall.
Gnats are actually part of the fly family and different gnat species can be found in every region of the United States. Most gnats prefer to live and breed outside, but you can find some gnats indoors, living in houseplants or congregating on your window screens or near your lights. In this article we will address the most common gnat species and provide information on the most effective ways to eradicate each one.
Gnats and Fruit Flies are different!
A common misconception is that gnats and fruit flies are the same thing. Although they may hover over your trash can, gnats do not feast on rotting produce or food like fruit flies. If fruit flies are your problem, go here to find out how to get rid of them.
Controlling the Most Common Gnat Species
To get rid of black flies, spray pyrethrin-based insect foggers in your yard. Also known as turkey gnats or buffalo gnats, black flies are commonly found in the wet northern climates of the United States and Canada between late April and July. These blood-sucking insects are tiny, black or gray, and have shorts legs and antennae. Pyrethrin-based foggers, like Raid Yard Guard Outdoor Fogger and Spectracide Bug Stop Insect Killer, are an efficient way to temporarily reduce the number of black flies near your home. Pyrethrin biodegrades more easily than other chemicals, but you should still use caution when spraying it near your home as some animals, especially cats, can be sensitive to pyrethrins. Unfortunately, black flies are resilient creatures, and no method has been proven to successfully kill them off for the long term. The most effective—albeit expensive—way to significantly reduce the black fly population is through large-scale aerial spraying.
To get rid of fungus gnats, check out that article and/or dry out your houseplants. Fungus gnats breed in soil and feed off of plants, and they thrive in the wet, warm soil found in houseplants.
To get rid of eye gnats, spray mosquito repellent on your clothes and body. Eye gnats are particularly annoying because they tend to swarm around our faces and fly in our eyes and mouths. They do not bite, but eye gnats have been known to spread acute bacterial conjunctivitis (“pink eye”) because they feed off of secretions found near the eyes of humans and animals. Eye gnats are typically yellow or black with a shiny appearance, and they are commonly found in warm, dry regions. Like black flies, eye gnats are very difficult to control, and aerial spraying of insecticide is the best way to reduce their population. Since most of us don’t have our own planes, we must rely on the temporary relief provided by insect repellents. Spray your body with a mosquito repellant containing DEET, such as OFF! Deep Woods Insect Repellent or Repel Sportsmen Max Formula. Never spray repellent directly on your face; instead spray it on your hands and then rub in on your face, avoiding direct contact with your eyes.
To get rid of aquatic midges, turn off outdoor lights around sundown. Aquatic midges (also known as chironomids or non-biting midges) are a type of fly that breeds in and around just about any aquatic environment, including rivers, ponds, lakes or storm drains. They are most active at dusk and look very similar to mosquitoes, but aquatic midges do not have a beak and do not bite. Although they are weak fliers, aquatic midges are easily carried by wind and can enter homes and buildings through screens or inadequately sealed windows. Since they are very attracted to light, the easiest and most effective way to reduce the number of aquatic midges around your property is to the limit your use of outdoor lighting. If possible, keep lights off from dusk until 45 minutes after sundown as this is when aquatic midges are most active. Since they are especially attracted to mercury-vapor lamps, you should switch to sodium-vapor or halogen lights with pink, yellow or orange tints. You might also consider installing decoy lights away from your house or main buildings to lead midges in the other direction.
Natural Ways to Control Gnats
Apple cider vinegar. To create an apple cider vinegar gnat trap, cut off the top third of an empty round plastic bottle (a 2-liter bottle works best). Fill the rest of the bottle with ½ cup of apple cider vinegar, a few drops of dish soap (ideally lemon-scented) and enough water to fill the bottle halfway. Insert the top third of the bottle upside down into the larger bottle to create a funnel (you may want to duct tape the pieces together). Gnats will fly down the funnel and into the bottle because they are attracted to the sweet-smelling apple cider vinegar, but they will have a difficult time escaping.
Vanilla. For a temporary gnat repellent to put on your body or clothing, mix one tablespoon of vanilla into one cup of water. This mixture is gentle enough to put near sensitive areas like your eyes, nose and throat. Be sure to use 100% pure vanilla extract without any added sugar or corn syrup.
Citronella. Plant the herb citronella in your garden to help repel gnats. You can also bring citronella plants inside. Citronella essential oils and candles are also effective at keeping gnats away.
Ways to Avoid Getting Bitten by a Gnat
- Wear long-sleeved shirts and long pants when spending time outside near wet areas like rivers, lakes or streams.
- Spray an insect repellent containing DEET on your clothing and body. (For children, use a repellent containing no more than 30% DEET.)
- Stay indoors at dusk, when gnats are most active.
- Use a fan while sitting on your porch or in your yard, since gnats are easily blown away by the breeze.
How to Treat a Gnat Bite
Not all species of gnats bite, but unfortunately some do. Gnats usually are not strong enough to bite through clothing, but their small size allows them to crawl on your body and under your clothing undetected. Soon after a bite, the bitten area will begin to swell and may bleed. The bite will become itchy and red, like a mosquito bite. If bitten, you should:
- Wash the bite with soap and water to get rid of any bacteria that the gnat may have carried from other plants or animals.
- Apply an antiseptic cream to the bite.
- If the bite is painful, use an ice pack to dull the pain.
- Apply an anti-itch cream to the bite or take an oral anti-itch medicine to help lessen itchiness.
Ways to Prevent Gnats from Coming Indoors
Install a high-quality “no-see-um window screen” on each of your windows.Leaving your windows open to let in fresh air is wonderful, but letting in gnats and other pests is not. Standard fiberglass or aluminum screens will succeed in keeping most pests out. However, since gnats are extremely tiny creatures, you may want to invest in a “no-see-um window screen,” which is specifically designed to keep out gnats and other miniscule insects. No-see-um screens are tightly woven with a finer mesh fiberglass to keep gnats out while still allowing fresh air in.
Repair any holes in screens or cracks in walls. Though they aren’t very intelligent, gnats are very tiny and they have a knack for finding small holes or cracks that will allow them to get inside. Be sure to periodically check your window screens for holes or tears and your walls for cracks, and promptly repair any problem areas.
Use a pasteurized potting soil. Fungus gnats breed best in the rich soil found in many houseplants. For this reason, you should use only pasteurized potting soil, since pasteurization kills gnats and the microorganisms they feed on. Be sure to store your pasteurized soil in a tight container to prevent it from becoming infested. Most bagged potting soil found at gardening or home improvement stores will be sterilized, but you should check the label for the words “pasteurized” or “sterile” to make sure.
Quarantine plants for 7 to 10 days before letting them into your home. When introducing new plants into your home, especially ones that have been kept outside, you should quarantine them in your garage or entryway and monitor them for signs of fungus gnat infestation before bringing them inside. Signs of infestation include tiny white worms on the surface of the soil and gnats hovering over the plants. If infestation is found, you should dry out your plants and rake the soil to kill the fungus gnat larvae. Once you’ve seen no signs of gnats for at least a week, then you can go ahead and bring the plant inside.
How to Prevent Gnats in Your Yard
Eliminate any standing water. Some gnats flourish in wet conditions, so reducing the sources of moisture in your yard and around your home will help prevent them from breeding. Put away anything that collects rainwater, such as birdbaths, buckets or children’s pools. Be sure to remove any clogs from your storm drains and gutters, as well.
Do not over-water your plants. If you must water your outdoor plants, try to do it as sparingly as possible. For most plants, you should allow the topsoil to completely dry before their next watering.
Turn off the lights. Gnats and other insects such as flies and moths are attracted to light, so you should try to limit your use of outdoor lighting, especially at dusk. Gnats are less attracted to sodium-vapor or halogen lights, so use them instead of mercury-vapor lights.