How To Get Rid Of Gnats In Your Terrarium

Nick Durante
by Nick Durante
Credit: Shutterstock / olsim photo

Building and maintaining a vibrant terrarium can be a lot of fun. However, a healthy terrarium comes with many roadblocks along the way, such as gnats. Understandably, you may struggle with how to get rid of gnats in your terrarium.

You can get rid of gnats in your terrarium if you set out a small dish with apple cider vinegar. The scent of the vinegar will attract the gnats, and they will drown in the liquid. It also helps to put sticky traps in the substrate and air your terrarium out if the substrate is too moist.

When in doubt, it’s a good idea to leave the lid off of your terrarium for a few hours so the gnats fly away. Follow along as we explore how to get rid of gnats in your terrarium.

Why Are There Gnats In My Terrarium?

The moisture, plants, and food remnants in terrariums attract gnats. Fungus gnats are most common in terrariums, but you may also find fruit flies. You’ll likely find gnats in your terrarium if you over-water the substrate and leave the lid off for a while.

The gnats will enter your terrarium in search of moisture, and they will stay to eat the plants. Unfortunately, fungus gnats can damage the plants in your terrarium after they run out of dead plant matter to eat. Fungus gnat larvae can even damage plant roots if you don’t take measures to get rid of them.

How To Get Rid Of Fungus Gnats In My Terrarium

1. Use Sticky Traps

The easiest way to get fungus gnats out of your terrarium is to use sticky traps. They are easy to use, and they quickly get rid of tons of gnats each day. Sticky traps typically come in bulk, so you can easily cover plenty of ground in your terrarium.

Yellow and sticky, these traps attract gnats with bright colors and kill them with the adhesive. You can find black sticky traps, but vibrant colors make it easier to trap and kill gnats. Granted, sticky traps won’t get rid of the larvae, but they will kill the gnats when they hatch and fly around.

2. Introduce Predatory Mites

What better way to get rid of gnats in your terrarium than to introduce predators? Hypoaspis mites are predatory and target fungus gnats and quickly eliminate them. Not only do they eat full-grown gnats, but mites will also target the larvae.

This helps control the active fungus gnat population and stop larvae from hatching. Ideally, you should put the mites in your terrarium at night or in the morning before it’s too bright. Try to put the mites in areas where you see a lot of larvae and gnats.

3. Air It Out

The results may not be immediate, but you can get rid of gnats in your terrarium if you open the enclosure. This requires some patience, but the fungus gnats will eventually leave your terrarium. Moisture will slowly leave the terrarium, so gnats won’t be as drawn to the environment.

Keep in mind that you must be careful if you air your terrarium out for more than 2-3 hours. After all, the last thing you want is to make your terrarium too dry. After a few hours, you may want to spritz your terrarium with a spray bottle to reintroduce moisture when the gnats are gone.

4. Swat Them

While it’s tricky, you can get rid of gnats in your terrarium if you swat them. Of course, you must open the terrarium to put a swatter inside. This lets you swat and kill the gnats, and there’s a great chance that some will simply leave the terrarium.

Keep in mind that you must be careful when you swat gnats in a terrarium. The last thing you want is to disturb the plants and damage the glass.

5. DIY Trap

Sometimes, all it takes is a little DIY ingenuity to kill the gnats in a terrarium. There is no shortage of options, but many people simply use a plastic container and some old produce. Put some old produce or sugar in a small plastic dish and cover it with a lid.

Next, poke small holes in the lid that are big enough for gnats to crawl into. Avoid making the holes too big, or else the gnats can easily fly out of the container and the trap won’t work. Place the gnat trap in a spot where gnats are most active in your terrarium.

6. Vinegar

Simple household items, such as vinegar, make it easy to kill gnats in a terrarium, especially if you get creative. Some hobbyists simply put apple cider vinegar in a dish to attract and trap gnats. That said, some gnats may be able to get out of the vinegar if nothing covers the dish.

In that case, you can cover the dish with a thin layer of plastic wrap with a few holes. Add some brown sugar or honey to the vinegar if the gnats don’t flock to it right away. Vinegar traps won’t harm the plants in your terrarium, and countless people report success with them.

7. Avoid Over-Watering

The more moisture there is in your terrarium, the more likely it is to attract gnats. Moisture control is one of the hardest parts of maintaining a terrarium, as mold and pests will thrive if there’s an imbalance. How often you water your terrarium versus how often you air it out affects how gnats will be drawn to it.

Keep in mind that the ideal watering schedule also depends on the types of plants you keep in your terrarium. That said, you don’t have to water terrariums as frequently if you keep them closed more often than not. For example, some people only water their terrariums once per month if they primarily keep the lid closed.

Other hobbyists mist the plants in their terrariums a few days a week to keep the substrate moist. Never soak the substrate or it will be hard to dry it out. The excess moisture will attract more gnats and hinder plant growth.

Summing It Up

The best way to get rid of gnats in your terrarium is to put sticky traps in the soil. You can also introduce predatory mites, such as Hypoaspis mites, to kill the gnats. It also helps to open your terrarium for 2-3 hours to air it out and get rid of gnats. Otherwise, you can trap and kill the gnats with apple cider vinegar traps.

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Nick Durante
Nick Durante

Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.

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