How to Catch and Trap Gnats

  • Written By Dan Edwards on February 2, 2021
    Last Updated: February 2, 2021

The Dalai Lama reputedly said,

‘If you think you are too small to make a difference, try sleeping with a mosquito.’

This could equally refer to gnats. Although extremely small, they’re incredibly annoying and tenacious. Whether it’s a swarm or one single gnat—an unwanted flying insect buzzing around your head or food can drive you crazy. Luckily, there are a few simple methods to catch these mini-monsters, both indoors and outside.

Catch and trap gnats with these methods:

  • Lure with apple cider vinegar
  • Attract them with a candle
  • Use sticky post-its with honey
  • Tempt them with wine

The Best Gnat Traps

Whether you’re going to buy a gnat-catcher off the shelf or are a creative type who wants to manufacture a bespoke catcher, there’s a method below to suit your needs. 

Apple Cider Vinegar

  1. Gather together a few old jars
  2. Inside each, place around 4 tablespoons of apple cider vinegar
  3. Put a few drops of dish soap into the vinegar and mix it with a spoon

Position these jars in areas of the home or garden where you have an issue with gnats — and wait. These flying pests, especially from the Drosophila family, which includes vinegar gnats, are attracted by the smell of the apple cider and fly into the jar to investigate.

The detergent breaks the surface tension of the cider, allowing the critters to sink into the vinegar and drown. Furthermore, it adheres to their legs, feet and wings, and prevents them from escaping.

Every day, pass the solution through a fine medium — such as a disposable coffee filter — to remove the dead gnats and allow you to reuse the trap.

If you wish, you can attach a length of string to the heads of the jars and suspend in the garden from trees and fences.

Ultraviolet Light Traps

You can use these straightforward and inconspicuous machines inside or outside.

The UV lights attract gnats, which then enter the trap and are prevented from escaping, usually through three different means:

  • A reverse-fan ‘sucks’ in the gnat as it approaches the light. The inside of the trap contains sticky pads from which the creature cannot escape
  • The gnats are electrocuted and die
  • A one-way entry system allows the gnats inside, but due to the design of the interior, they cannot escape. The insects can then be released away from your home if you’re against injuring them


An alternative to using a store-purchased UV light is to use a house candle.

  1. Find a small bowl
  2. Half fill it with water
  3. Add a little detergent, again, to break the surface tension
  4. Stand a candle in the center of the bowl and light it

Ideally, switch off as many electric light sources in your home as you can. The fewer there are, the more likely the gnats will head to the candle. You can tell your partner you’re being romantic, not treating insect infestations.

This has a two-pronged effect. Firstly, some gnats will fly to the flame attracted by its brightness, burn their wings and fall to their death. Secondly, other critters will aim towards the candle and see their reflection in the water beneath. Curious, they’ll drop down to investigate and drown in the liquid.

This method is equally effective outside, although you may end up attracting more gnats than you started with.

Banana Trap

  1. Slice up a banana — the riper, the better
  2. Place the small fruit segments into the bottom of a glass jar and cover the top with some plastic wrap
  3. Poke around ten small holes into the wrap with a pencil tip

The fermenting banana will attract the gnats, entering the jar through the spaces in the plastic. As long as you don’t make the holes too large, the gnats will be unable to escape.

This is a useful method if you’re against killing the gnats, allowing you to release them elsewhere. Alternatively, if you do wish to end their lives, poke the head of your faucet through the plastic wrap, half fill with water and then swill around. Empty the jar down the sink and run the tap for a few seconds.

Sticky Cards

Not only do gnats love vinegar, but they also adore anything yellow.

Research shows that these creatures have an insatiable attraction to this color. This is possibly because it’s a sign of a weak plant with poor defenses, hence susceptible to insect predators.

You can purchase commercially available yellow sticky pads or glue sticks that are covered in a non-drying glue. The gnats flock to the irresistible hue, land, and become stuck.

Alternatively, you can make your own:

  1. Get hold of yellow post-it notes or index cards and coat with honey
  2. Position them in areas where the gnats congregate
  3. Ensure they’re horizontal; otherwise, the honey will drip off

If you have an issue with fungus gnats, which swarm around outdoor shrubs, greenhouse seedlings and houseplants, make a small addition:

  1. Poke a straw or chopstick through the center of the yellow cards
  2. You can then plunge the other end into the soil around the suffering plant.

Alternatively, these yellow plant pot sticky traps can work really well.


It’s a beautiful summer day. You’re out in the garden and uncork some red wine to enjoy while you relax in the sunshine. Almost miraculously, gnats begin to congregate around your glass and the open bottle.

Sounds familiar, right?

Not only are these tiny beasties annoying, if they land in the wine, but they also alter the taste. Research published in the Journal of Chemical Ecology explains that female gnats, seemingly loving the alcohol, become over-excited and releases pheromones, which mars the flavor of your beverage.

To prevent this from happening, give the gnats their own glass:

  1. Get an empty plastic soda bottle and cut in half
  2. In the bottom section, pour in around 2 tablespoons of wine — not too much, otherwise, what are you going to drink?
  3. Take the removed top half, invert, and push into the bottle bottom — effectively making a funnel

The gnats will fly down through the opening into the wine. Ideally, they’ll drown. If not, and they decide to go home to sleep off their evenings’ drinking, they’ll struggle to leave through the narrow hole.


With readily available household materials, you can make simple and highly effective gnat traps. Whether spending time indoors or relaxing the garden, you can eliminate the annoying pests and enjoy a gnat-free experience.