How to Get Rid of Gnats for Good
Gnats are among Mother Nature’s tiniest creatures, and, as with other miniscule minions, are among her most detested. They fly in your face, come in for a landing in your ear canal, swarm around the pets and lay siege against everyone at the picnic table.
They’re so pervasive, humans can’t even catalog all the various species of them. Entomologists gave up on that long ago, deciding to group numerous sub-species of the flying critters under one heading. Of course, they had to give them a name with more syllables than just “gnat,” so they’re listed as Nematocera.
But we’ll just call them gnats.
Now, back to the part about nobody liking them. They’re actually more damaging to plants than humans, but their nuisance level puts them as candidates for immediate and thorough eradication. We’re going to discuss methods for getting rid of gnats, but as to how immediate and how thorough these techniques are, well, we’ll let you be the judge.
But we have to do something, right?
Yes, we do. So let’s get started and learn how to get rid of gnats for good.
Getting Rid of Gnats
Below you’ll find out how to get rid of gnats using commercial products and how to get rid of gnats using ingredients you already have lying around the house. You’ll also find some gnat killing solutions that make things better for a few days and some other gnat killing strategies that will make things better for longer (but never once and for all, sadly).
These are not ranked. But they are good. One gnat killing technique may work better for you than another, but whatever you do, don’t let the little buggers win. Fight back! Kill the gnats!
Looking to get rid of flies and fruit flies? Our article on the Best Fly Traps might be better for you instead.
How to Kill Gnats
The Best Gnat Killing Products
1. Gnat Killing Fly Paper
Messy, unsightly and out of place regardless of décor theme, fly paper nevertheless is effective against small to medium-sized gnat infestations. The most recommended brand of fly paper is Black Flag. Black Flag is the one of the icons of the pest control business, proud to be the company that brought the world the Roach Motel (roaches check in, but they don’t check out).
While there are dozens of variations to the fly paper idea, the Black Flag version is probably the most user-friendly version out there. The sticky paper spirals out of a can and hangs via a nifty red ribbon.
There are no robustly toxic substances in the Black Flag fly paper. It’s coated with natural and synthetic resins in mineral oil, and when flies and gnats land on it, they’re stuck for the rest of their life (which is only about two weeks, even in optimum conditions). You can use the fly paper outdoors and indoors.
If you thought the Black Flag fly paper made a gauche fashion statement, get a load of this stuff. It looks like a slice of American cheese that had been mistakenly used as a lint roller. The Negarly fly paper is a 6×8 sheet of thin polyethylene that is treated on both sides with a super sticky goo that holds anything that flies into it – flies, gnats, mosquitoes, lady bugs, bees, moths and flecks of dirt that gets picked up by the wind.
It may be ugly, but it works beautifully. Non-toxic ingredients attract flying insects to it, and weather-resistant adhesive makes sure they get their gnarly little feet hopelessly stuck. The color yellow is considered to be an attractant to a wide range of flying insect, like gnats, leaf miners, houseflies, fruit flies, midges and their ilk.
Of course, the inherent disadvantage to fly paper or devices that trap insects in adhesive is that everything gets stuck – even your fingers if you’re not careful. Vegetable oil or waterless hand cleaner will help clean off your fingers if that happens.
2. Make Your Own Gnat Killing Fly Paper
It’s probably not the cost of commercial fly paper that makes trying a do-it-yourself project appealing, it’s the fact that you return home from the store and realize you forgot to buy it, or you couldn’t find it in a 180,000-square-foot cavern of a box store.
So here’s the recipe for DIY fly paper:
(These ingredients make a surprisingly large batch, so if you don’t want a lot of fly paper, cut the ingredients by a third or half).
Cut a brown paper bag into strips, combine the ingredients in a saucepan and turn on medium heat. Stir until the sugar has completely melted. Remove the saucepan from the heat. Dip the strips of paper bag (you can use most any heavy paper) until they are completely soaked.
Remove the strips of paper carefully with tongs and lay them on something that suspends them above the surface (this enhances drying). Poke a small hole in one end of the paper strip and guide a string or length of yarn through the hole and make a loop 4-5 inches above the paper.
Make sure you hang these away from traffic areas and understand that all sorts of flying insects might be attracted to your homemade fly paper, and that includes undesirables like bees, yellow jackets, bumble bees and wasps.
3. Gnat Killing Bug Zappers
Yep, bug zappers – the second most popular spectator sport in the southern U.S., right after NASCAR, but also a good way to kill gnats.
But here’s the thing – don’t buy a bug zapper just for gnats, unless you have swarming clouds of them. A bug zapper will definitely kill gnats, but it’s really overkill for the job. However, if you also have a mosquito problem, or a housefly or horsefly problem (pretty common around livestock), then you might as well invest in one of these electronic lightning generators.
Bug zappers used to be strictly an outdoor attraction, but manufacturers now make them safe enough for indoor use. Some models are strictly outdoor and some are strictly indoor, but some can be used indoors or outdoors. This is one of them.
An insect is attracted to the device by an ultraviolet light and then when they light on the charged grid – ZZZT! – no more bug. For a device that’s safe to use indoors, it’s hard to imagine that the grid is charged with 4200 volts. But the electrical parts are enclosed, out of reach, and the grid is grounded. Electricity always wants to run to ground, like water always seeks to run downhill.
The 20-watt UV light attracts insects for 2100 square feet, and includes a liquid mosquito attractant, which emits an artificial pheromone (scent) that attracts mosquitoes. (The scent does nothing for gnats, but you’re not buying the device strictly for gnats anyway.)
So if you have trouble with gnats AND mosquitoes, this might be a good option, but read the following snippet:
Are Bug Zappers More Trouble Than They’re Worth?
Bug zappers have their detractors, who say that they kill too many beneficial insects along with the mosquitoes and gnats. One research project found that only 31 percent of the dead insects collected from bug zappers were mosquitoes and gnats. The rest were harmless bugs, some of which eat mosquito larvae.
They also claim that the ultraviolet light attracts more mosquitoes to the yard than would ordinarily be there. Plus, they say, the carbon dioxide emitted by humans is a stronger attractant, and once they come in range of human odors, they forget about the ultraviolet light and head straight for the human.
The study, and others like it that came to the same conclusions was performed roughly 10 years ago. Manufacturers have upgraded their products since then, included artificial pheromone packets and therefore resolved (or so they say) those early complaints.
The jury’s still out on that.
4. Homemade Gnat Trap
Careful! It’s a trap! Yeah, a homemade gnat trap…
So, fly paper is messy and unsightly and bug zappers claim too many innocent victims. What else is there to kill gnats?
Trap those little gnat beasties. As with the homemade fly paper, you can lure gnats to a sugary treat, and when the gnats commit, the gnats get stuck. But this time, it’s not with adhesive but with a sticky soap that weighs gnats down and prevents the gnats from flying.
This homemade gnat killer is super-simple:
Lightly stir all the ingredients in a shallow dish (one you can spare) and set in a window ledge, kitchen counter, patio table or flat porch railing and wait for the gnats.
The gnats will come in for a swim, and never fly out again. Set two or three traps out in places were gnats (or other undesirable insects) have caused problems and maybe, just maybe, you’ll eliminate the gnat problem.
5. A Commercial Gnat Trap
First off, it’s not a bug zapper. This is a zap-free product. It’s legitimately a trap. It uses ultraviolet light to lure insects into the cylinder, and then when they touch down at the base, they get stuck on glue board.
It’s safe enough to use around food. In fact, placing it in the vicinity of food that typically attracts gnats is recommended. The light is not particularly powerful, so running it at night in a darkened room will provide the best results. It runs on low power. The unit ships with a power supply that delivers current to the unit via a micro USB cable.
This is advertised to reduce the number of pests, not kill them all. Houseflies are too big, and generally are able to break free from the sticky fly paper. But gnats, ants and fruit flies are fair game, and that is what the product was designed for.
The glue board discs at the bottom are easily replaceable, and you can see for your self that the unit works after a quick glimpse at the insect bodies strewn about on the surface.
This product takes the rectangular yellow sticky-pad notion a step further with butterfly-shaped insect traps that you can plant in the same soil as houseplants or hang on a hook. There is sticky adhesive on both sides, and the yellow color attracts gnats, fruit flies, aphids, leaf miners, white flies and other creepy flyers.
The adhesive is protected under a plastic sheet that you peel off when you’re ready to use the trap. This comes with 30 glue pads, 15 lengths of hanging wire and an adorable little yellow shovel to help set them in the soil.
How to Use Gnat Killers More Effectively
To get the most out of the commercial insect repellants / traps / zappers, you must make sure they are the star of the show when it comes to attracting pests. Any competing element, such as food (particularly fruit and sugary food), a brighter light than the one emitted by the product or a stronger smell than the one emitted by the product will draw the insects away from the devices.
For example, if you have a basket of bananas on the kitchen island and a yellow insect trap hanging 10 feet away in the corner of the kitchen, guess which attraction is going to get the action. If you use one of those traps with the ultraviolet light in the sunroom and you have a bright setting sun in the window, the insects won’t even notice the trap. Or, if you’re trying to clear insects out of a patio area and all your guests are peering into their cellphones, the screens from the cellphones are going to be bigger attractions to gnats than the insect traps.
The best results are obtained when the traps and devices are by themselves with no competition around them. If the trap has an attractant that releases a pheromone, make sure you replace the attractant on a regular basis to keep a fresh scent (to them) going. The product literature will provide that information. There should be no competing smells – like those coming from humans and their pets – in the area.
The Nuclear Gnat-Killing Option
For a quick clear-out of gnats (but don’t expect it to be a permanent solution) a can of bug killer works wonders. But you can guess the negatives to this technique.
New environmentally safe* sprays are jostling for position in the marketplace, and some are worth a look. (*We’re going to step back from saying environmentally “friendly”). The area affected by the spray will be temporarily hazardous, but to a small, manageable degree.
An additional problem to assaulting gnats with a killing spray is actually hitting them with it. Gnats are tiny, agile and quick, and if you’re going to be the best gunslinger in the west, you’ll have to prove it to the gnats. Some products aren’t really made for knocking gnats out of the air, but for creating a perimeter that kills and repels at the same time.
Be that as it may, here are some of the best brands of insect spray that you might want to try:
- Black Flag Kitchen Bug Killer – Designed for use specifically for killing gnats and other flying insects.
- Ortho Home Defense – This is a good all-purpose product that protects against a variety of insects. Spray it on door thresholds, window ledges, baseboards, crown molding, welcome mats, porches, around potted plants and anywhere bugs gather.
- Eco Defense Organic Home Pest Control Spray – It’s organic and very effective against a number of insects. For gnat control, it’s hit or miss. The best way to use it against gnats would be to spray it around plants that gnats like to gather at. (You’re not going to shoot them out of the sky with this stuff.)
- Orange Guard Indoor / Outdoor Pest Control – The formula contains no harsh chemicals, and the base is water. It’s safe to use in areas where pets rest, and around plants. It kills or repels a long list of insects, but gnats are not listed among them in the product literature. Applying it to the soil around plants is going to be your best option for gnat control.
- Raid House and Garden Bug Killer – RAID!! That’s the cry that goes out in the insect world when someone uses a Raid product. This can be used against swarms of gnats in the air as well as around plants and other insect-attracting features in your home and garden. Be sure to get the House and Garden variety, and don’t spray this around food or edible crops.
Other Methods for Killing Gnats
1. Get ‘Em Drunk
We’re kidding, but not totally. If you’re one of those extremely rare people who doesn’t finish off a bottle of wine before it turns to vinegar, you can use that expired wine to make an effective gnat trap.
It’s so easy, you can do it, well, when you’re not at your sharpest. Just pour some stale wine (or apple cider vinegar) into a vessel. It can be a shallow dish or a deep decanter (It doesn’t seem to matter), add a few drops of dish soap and set the dish at a convenient and easy-to-access location.
Gnats and other sugar-loving bugs will come congregate at your trendy little wine grotto, and when they try to leave, they’ll discover that the bartender snagged their keys and hid them under the bar towel.
2. As the Flame Draweth the Moth (or Gnat)
You know those candles you have in the junk drawer of your kitchen that you keep in case of a power outage? You’ll never remember they’re there when the lights do go out. So put them to good use and employ them in the honorable service of gnat control.
It’s as simple as striking a match. Just stand a candle up in a small bowl or cup, fill the cup with water and perhaps a tiny amount of dish soap. Light the candle and turn off all competing lights if possible.
Gnats, moths and other bugs will be drawn to the flame and will either get torched in the fire or fall into the water, unable to escape.
Use all diligent precaution with the candle, of course, and don’t go to bed with it still burning.
3. Repurpose that Kroger Bag
Do you have a collection of plastic grocery store bags? Of course you do. How about fruit that’s past its prime? Probably.
Take fruit that you won’t eat because it’s gone mushy or has started to rot, put it in a grocery bag (or any plastic bag), twist the opening to seal it and poke tiny holes in the bag with a fork. Be careful not to make the holes too big.
Gnats will be attracted to the fruit and will crawl inside the bag. They’ll check in, but they won’t check out.
Tips for Getting Rid of Gnats
Perhaps the best defense against gnats is to let them know they’re not welcome in your home and garden. It’s much easier to deal with a potential problem than a developing one. Below are some tips from the Arizona Cooperative Extension that will help make your home as gnat-free as possible.
Monitor and Destroy Gnats Early and Often
Gnats are so annoying, it’s hard to imagine not noticing them, but in the early stages of an infestation you might not.
When you water your plants, tap or shake the stems and leaves and see if a swarm of gnats take off in flight. Put a potato slice in the soil, and check to see if gnat larvae move in to feed.
You won’t need to know what gnat larvae looks like. You’ll know them when you see them.
Gnats are easier to control when you catch them in the larvae stage. There are a couple of biological control agents you can use at this stage – steinernema nematodes and hypoaspis mites. The steinernema nematodes enter a gnat larvae’s body and destroys it from the inside. The mites feed on gnat eggs.
There are chemical agents available, such as bacillus thuringiensis, which is applied to the soil around a plant. The agent slowly kills gnat eggs and larvae in the soil via a naturally-occurring bacteria.
If you go to your local home and garden box store and ask a store employee for any of these agents, you’re likely to get a blank stare or be directed to an aisle that doesn’t exist. The best thing to do is contact your county extension office, and they should be able to help you find sources for these agents.
Gnats Like Wet – Don’t Let Them Have It
If you live in the humid south, you already have a problem with excess humidity, and unfortunately, you’ve probably gotten used to it. But that is at the heart of the problem when dealing with insect infestations.
Most of the time, a good central air conditioning system will help keep moisture levels down, but in periods when the humidity is thick enough to cut with a butter knife, the AC system becomes overwhelmed. Plus, AC systems don’t run all the time, so when they’re off, they’re not dehumidifying.
You should get a dehumidifier for reasons that go beyond gnat control. Mold and mildew thrive in humid conditions, and running a dehumidifier as a supplement can held control their growth, plus make the home less hospitable to flying insects.
When you water your plants, don’t over-water. The soil should be dry on the surface 24 hours later. If it’s still wet, you’re over-watering your plants.
Shut the Front Door to Gnats
This should be a no-brainer. If you don’t want flying insects in your house, don’t invite them in by leaving doors and windows open.
Also, before bringing store-bought houseplants indoors, inspect them for bugs. Look under the leaves and check the surface of the soil for insect larvae or even adult insects. Don’t bring the plants indoors until you’ve remedied the problem.
Gnats are already a nuisance, right? And many people don’t know this but gnats can actually bite! And when they bite (not all species of gnats bite, but the ones that do – ouch!) they often leave red bumps on the skin. In rare cases, gnat bites can even lead to severe allergic reactions. So, look for small red bumps on the skin, you may just have a gnat bite. They can itch or inflict pain and will often swell and even release blood or pus.
Treat the affected area with soap and water, but pat the area dry, rather than rub it with a towel. In cases where inflammation is pronounced, apply a cold compress for 10 minutes. Repeat if the symptoms return.
You can also apply anti-itch cream, like calamine lotion, and if an allergic reaction occurs, administer antihistamines as directed by the label.
It’s extremely rare, but there are occasions where you may need to seek medical attention. Bites around the mouth and eyes sometimes develop complications, and some symptoms are stubborn, and remain for up to two weeks. If you experience any of those situations, don’t hesitate to see a doctor.
Here are additional sources that you might consider. Enter these in your search window and add “file type: pdf” for the more scholarly articles. Good luck and good gnat hunting!
- World Health Organization – Mosquitoes and Other Biting Diptera
- University of Illinois – The House Fly and Other Filth Flies
- Clemson University – Gnats: Home and Garden Information Center
- California Department of Health – Nuisance Flies
- Purdue University – Biting Midges: Public Health and Medical Entomology
- Healthline – Gnat Bites:Treatment Options and Prevention Tips
Killing Gnats – Last But Not Least
Gnats get misidentified all the time. Sometimes, people call them fruit flies and visa-versa. But the thing is – it doesn’t matter if you call them the right genus and species. You just want to get rid of them.
So, for discussion purposes, we’re just going to group together all tiny, flying pests as gnats, whether they’re actual gnats, fruit flies or midges (also known as no-see-ums or punkies). Generally, what works for one of these species will work for the others.
The control techniques suggested by the Arizona Cooperative Extension office are proven winners, but by no means the definitive end-all list of tips. Your own state’s extension office probably has additional measures and resources you can try.
So try these tips as well as the other gnat-killing techniques and let us know how it works out from you. Please leave your comments in the comments section below, we’d love to hear from you!