Crafting Effective DIY Gnat Traps

Crafting Effective DIY Gnat Traps

With summer comes warm weather and more time spent outdoors. However, summer also brings tiny flying pests known as gnats. Although they may seem harmless, gnats can be annoying when they swarm around food or get caught in your drink. 

How Do Gnats Reproduce So Quickly?

One of the reasons gnats seem to multiply exponentially is their short lifecycle. Most common house or fruit fly gnats have a complete lifecycle from egg to adult in about 10-14 days. The females can lay around 100-200 eggs at a time in moist, organic material like rotting fruit or plant debris. The eggs hatch into larvae with no legs that feed on microorganisms and decompose organic matter. Within ten days, the larvae will pupate and emerge as adult gnats ready to breed. Their rapid reproduction allows populations to balloon quickly if food sources are abundant and conditions remain favorable.

Identifying gnats

Before going over DIY gnat trap recipes, it’s important to properly identify the type of gnat you’re dealing with. The two most common indoor house pests are fungus gnats and fruit flies, both of which are attracted to moist environments and rotting organic materials.

Fungus Gnats

  • Tan or grayish-black flies, 1/8 to 1/4 inch long with long legs and antennae
  • Often found near houseplants or potting soils
  • Larvae feed on fungi, mold, and decaying plant matter in moist soils

Fruit Flies

  • Small (~1/16 inch) black flies with red eyes
  • Commonly found near overripe or rotting fruits and vegetables
  • Larvae feed on fermenting fruits and vegetables

Proper identification helps ensure you target the right lure and conditions for the DIY traps.

DIY Trap Recipe 1: Apple Cider Vinegar Trap

One of the most basic yet effective homemade gnats traps uses apple cider vinegar. The acid in the vinegar mimics the fermentation attractant of rotting fruits and vegetables to lure both fruit flies and fungus gnats.


  • 1 cup apple cider vinegar
  • Container (jar, cup, vase)
  • Plastic wrap or Parafin paper
  • Rubber band or String (to secure wrap)


  1. Pour the apple cider vinegar into your container.
  2. Cover the opening of the container very tightly with plastic wrap or parafin paper and secure with a rubber band or string. Make several small pinpricks in the covering with a thumbtack or toothpick.
  3. Place the trap near areas where you’ve seen gnats congregating, like houseplants.
  4. The gnats will be attracted to the vinegar scent but not able to escape once they fly through the pinpricks to get to the vinegar.
  5. Replace the trap every 2-3 weeks as it fills up with drowned gnats.

With some vinegar and a few household items, you’ll have an effective DIY monitoring and control solution. The tiny holes allow gnats access to the vinegar scent but prevent escape, providing a natural way to reduce populations over time.

DIY Trap Recipe 2: Wine Trap

For a trap that’s somewhat more elegant than plain vinegar, try this gnat-catching wine trap. The fermented wine scent serves as an even stronger attractant for many types of fruit flies and fungus gnats.


  • 1 cup white wine (cheap works best)
  • Clear container (glass or plastic cup)
  • Plastic wrap
  • Rubber band


  1. Pour the wine into your container until about 3/4 full.
  2. Cover the opening with plastic wrap and secure tightly with a rubber band.
  3. Use scissors or a thumbtack to poke 6-10 small holes in the plastic wrap covering.
  4. Place the wine trap where you’ve seen gnats around your home, like the kitchen.
  5. Gnats will be drawn to the wine odor and fly in through the holes but not able to access the way out.
  6. Change out the wine every 1-2 weeks as needed.

Besides being a little more appealing than plain vinegar, the fermented wine is highly attractive to pest gnats. This trap provides effective control without using any chemicals.

DIY Trap Recipe 3: Yeast Trap

If fungus gnats are your main problem in houseplants, crafting a simple yeast-based trap may be the most targeted solution. Yeast mimics the fungi, mold, and microscopic organisms larvae feed on in moist soil.


  • 1/4 tsp active dry yeast
  • 1/4 cup warm water
  • Clear container (jar, cup)
  • Plastic wrap
  • Toothpicks or pieces of pasta


  1. Mix the yeast into the warm water until dissolved. Let sit for 5 minutes until foam forms on top.
  2. Pour the yeast mixture into a container, leaving some headspace.
  3. Cover the opening with plastic wrap and secure it with a rubber band or string.
  4. Poke 6-10 toothpick-sized holes through plastic covering.
  5. Place trap near houseplants. The foam and yeast will attract larvae, while holes allow access but no escape.
  6. Change every 1-2 weeks and monitor houseplant soils for drying out.

By targeting the yeast microbes larvae feed upon, this is a great natural solution for controlling fungus gnat root pests in potted plants.

DIY Trap Recipe 4: Mushroom Compost Trap

If your yard or garden is dealing with swarms of gnats, another effective trap recipe utilizes mushroom compost to attract both adult flies and larvae. The rich microbial activity provides an ideal food source.


  • 1/2 cup mushroom compost
  • Plastic cup or container
  • Plastic wrap
  • Rubber band
  • Water


  1. Add the mushroom compost to your container, packing it down slightly.
  2. Mist the compost lightly with a few sprays of water to provide moisture.
  3. Cover the container tightly with plastic wrap and secure.
  4. Poke 6-10 small holes through the plastic with a thumbtack or pin.
  5. Place the trap on the soil surface or hanging from a tree branch near gnat problem areas.
  6. Swarming adults and larvae will be drawn to the compost to enter through holes but not escape. Monitor and refresh compost every 7-10 days.

This trap works well for targeting large populations outside, utilizing the microbial activity gnats are attracted to for feeding and breeding habits.

FAQ 1 – How long do DIY traps work?

The effectiveness of homemade gnat traps will vary depending on factors like temperature, humidity levels, and severity of infestation. However, as a general guideline:

  • Vinegar and wine traps – Replace liquid every 1-2 weeks as it becomes saturated with drowned gnats.
  • Yeast traps – Refresh yeast mixture every 5-7 days as it breaks down. Monitor for drying out.
  • Compost traps – Refresh mushroom compost every 7-10 days or as it dries out.

Consistency is key to these low-maintenance monitoring and control methods. By providing a sustained attractant source and altering recipes periodically, DIY gnat traps can help reduce populations over weeks or months with regular use and replacement.

FAQ 2 – Can essential oils be added to traps?

Many essential oils have insect-repelling properties that could further enhance homemade gnat traps. Some oils that may help include:

  • Mint – Repels many flying and crawling insects. Add 5-10 drops mint oil to vinegar, wine or water traps.
  • Lemongrass – A powerful gnat deterrent. Use 3-5 drops of lemongrass oil in solutions.
  • Eucalyptus – Repels mosquitoes and some fly species. Add 2-3 drops of eucalyptus oil per trap.
  • Clove – Creates an aroma mosquitoes and gnats tend to avoid. 1-2 drops of clove oil per trap.

Use caution as some essential oils can burn plastic. Test a small amount first. Only use food-grade oils and never use near kids/pets. Oils may help repel pests from entering homes while traps remove those already inside.

FAQ 3 – How can I prevent future gnat problems?

Once gnat populations have been controlled using homemade traps, it’s important to address any conditions attracting them to prevent future issues. Here are a few tips:

  • Remove decaying organic matter like fallen fruit, old plants, or yard waste that can harbor insects.
  • Improve drainage of houseplant soil that may become waterlogged. Allow pots to dry slightly between waterings.
  • Use tight-sealing lids on garbage cans and clean waste frequently.
  • Fix any rainwater runoff pooling near foundations.
  • Use screened windows and doors where possible during warm months.
  • Consider sterile potting soil for plants to reduce fungi/mold gnats feed on.

FAQ 4 – Will commercial traps work too?

While DIY traps provide an inexpensive and environmentally friendly solution, there are also some commercially available gnat traps that can be effective:

  • Sticky traps – These cards or strips are coated in a very sticky adhesive that traps flying insects. Place near problem areas. Inspect and replace every 1-2 weeks.
  • Pheromone traps – Some traps emit synthetic sex pheromones that attract and capture male gnats. Hang these according to package directions.
  • Bti tablets – Tablets containing Bacillus thuringiensis israelensis (Bti) are a biological larvicide lethal only to mosquito, black fly and fungus gnat larvae when consumed. Add to standing water or moist soils.
  • Mosquito dunks – Similar concept to Bti tablets, these donuts of Bti release a bacteria lethal to gnat larvae over 30 days when added to ponds, horse troughs, fountains etc.

While commercial options provide convenience, DIY methods offer a low-cost, non-toxic approach. Combining different trap types gives the best results.

FAQ 5 – What natural repellents work against gnats?

A few plants with strong aromas can help repel gnats from entering homes when grown near entrances:

  • Citronella – Grows as a grass but oils in leaves repel many insects, including gnats.
  • Lavender – Soft floral fragrance helps mask attractants gnats follow into houses.
  • Basil – Sweet herb smell deters gnats and other flying pests.
  • Mint – Fresh mint sprigs or an essential oil-based room spray with mint can deter invaders.
  • Catnip – The nepetalactone oil in catnip is highly repellent to mosquitoes and some flies.

Placing potted plants of citronella, lavender, or mint near doors, venturing some mints in garden beds, or tucking catnip amongst plants creates a natural barrier against swarms entering.

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