How to Get Rid of Fruit Flies in Reptile Tank? (Get Rid of Gnats)

If you’re a reptile owner, you understand the unique joys and challenges that come with caring for these captivating creatures. Yet, one persistent issue may be putting a damper on your experience—fruit flies in the reptile tank. It’s a common nuisance but fret not. By following the guidelines discussed below, you can effectively tackle the problem and provide your reptile with a healthier, more comfortable living environment.

What are Fruit Flies?

If you see any small flies in your kitchen, they are probably fruit flies. They can also be found in your reptile tank and can be very problematic. These flies are attracted by the rotten fruits and vegetables found in your reptile tank. 

An adult fruit fly has red eyes and it is no more than one-eighth of an inch in length. The front body is tan in color while its back is black. These flies can lay five hundred eggs approximately. It takes a week to complete the egg to reach the adult life cycle. 

These flies lay their eggs near the surface of fermenting foods or other moist organic materials where the tiny larvae continue to feed on the fermenting mass to thrive properly. 

What are Fungus Gnats?

Some people misidentified fungus gnats as fruit flies that are common in reptile tanks coming in with the food. These gnats look mosquito-like and have a shorter life span. These small and dark flies grow to approximately one-eighth of an inch and have long legs and antennae.

The forewings of such flies show a Y shape pattern. These gnats have small larvae with a black head and they may lay two hundred eggs approximately with a seven to ten-day life cycle. These flies live throughout the year.

Fungus gnats will not bite or transmit diseases to humans but they can be very frustrating with the larvae causing serious damage to the plants found in your house and reptile tank. 

Are Fungus Gnats and Fruit Flies Dangerous to Pet Reptiles?

Contrary to some beliefs, fruit flies pose no harm to your reptilian pets. These tiny, quick-breeding insects are not venomous and don’t carry diseases that can affect reptiles. Reptiles are not averse to having them around, and some, like small geckos and anoles, might even consider them a delicious snack!

Fungus gnats, similar to fruit flies, do not pose a direct threat to your pet reptiles. While their larvae can cause damage to plant roots if you have live plants in your reptile’s enclosure, they are not harmful to the reptiles themselves.

These gnats can, however, be indicative of overly moist conditions, which might lead to other problems such as mold growth or bacterial infections. So, their presence should alert reptile owners to potential care and habitat issues, rather than health threats to their reptiles.

Why do Fruit Flies and Fungus Gnats Appear in Reptile Tanks?

Firstly, the conditions within a reptile tank are often inadvertently the perfect breeding ground for these insects. Both fruit flies and fungus gnats thrive in warm, moist environments – a common setting for many reptile enclosures.

The humidity that your reptiles enjoy is also the same environment that these gnats and fruit flies find irresistible. They seize the opportunity to multiply in these conditions, leading to their unwelcome presence in the tank.

The presence of food sources in the reptile tank significantly contributes to this issue. Leftover food items, especially fruit or vegetables, are a veritable buffet for fruit flies. They are attracted to these items and will gladly lay their eggs on them.

Similarly, fungus gnats are drawn to organic matter and damp soil. They are not picky; they can feed on plant roots, leaf litter, and other decomposing organic material within the enclosure. Simply put, your reptile’s tank could be inadvertently hosting a gnat feast.

How to Remove Fruit Flies and Fungus Gnats?

It is not so easy to get rid of such pesky flies but you have to find the best way to get rid of them without causing damage to your pet reptile. There are several ways that you may use to get rid of such flies and gnats.

1. Remove Uneaten Food

Try to remove the uneaten food lying around your reptile’s enclosure as soon as possible because this uneaten food attracts the fruit flies. Remove rotting fruits from the home and your reptile’s enclosure because flies are attracted to the fermenting food that you may have not noticed lying at the back of the enclosure.

Try to wash the dishes inside your reptile’s enclosure quickly because a slight hint of rotten fruits and vegetables can attract gnats and it may be getting difficult for your lizard.

2. Thoroughly Clean the Tank

Your first course of action should be a deep, thorough cleaning of the tank. I’ve witnessed countless hobbyists underestimating the importance of this step, but I stand firm on its significance.

  1. Empty the tank: Begin by carefully moving your reptile to a safe, temporary enclosure.
  2. Clean the tank: Next, scrub every inch of the tank with a reptile-friendly disinfectant. Pay extra attention to corners and crevices as they are potential hideouts for eggs and larvae.
  3. Rinse thoroughly: Rinse the tank multiple times to make sure no residue of the disinfectant is left, as it can harm your pet.

3. Replace Substrate

The tank substrate is a perfect breeding ground for fruit flies and fungus gnats. Ergo, replacing the substrate is a step you simply cannot afford to skip.

  1. Remove old substrate: Dispose of the old substrate carefully to prevent any lingering flies from escaping into your home.
  2. Install new substrate: Replace it with fresh, clean substrate suited for your reptile.

4. Treat the Water

Fruit flies and fungus gnats are attracted to stagnant water. A smart move, therefore, is to treat the water in your reptile tank.

  1. Empty and clean water dishes: Remove all water dishes, clean them thoroughly, and fill them with fresh water.
  2. Consider a water conditioner: Use a reptile-safe water conditioner to discourage the flies from laying eggs.

5. Use a Natural Fly Repellant

There’s a multitude of natural fly repellants that are safe for your reptile and effective against flies. You can use insect sprays but make sure it is eco-safe such as Eco Defense Home Pest Control Spray.

  1. Consider diatomaceous earth: A light dusting of food-grade diatomaceous earth on the substrate can help kill any remaining flies or larvae.
  2. Leverage fly traps: Non-toxic sticky fly traps can also be used around the tank to catch any adult flies.

6. Use a DIY Trap

DIY trap is a do-it-yourself trap. Many reptile owners make their DIY traps which are very effective and overall safe to use. You can use fruit juice or apple cider vinegar. You have to use a small bowl with a drop of dish soap.

Cover the top of the bowl with a tight wrap, using an elastic band. Make sure that your reptile does not climb on it and break it. Using a toothpick, make some holes on the edges of the bowl. This will help to stop these flies from crawling out the holes once they have climbed in. 

8. Use Fly Traps

To eradicate pesky flies, reptile-safe fly traps such as KATCHY Indoor Insect Trap can be a great solution. This is a stylishly designed fly trap that can be put in your home with confidence. To use this, you have to set it close to your reptile’s enclosure and turn off the lights to get better results.

9. Keep the Soil Dry

While you are using a soil substrate in your reptile’s enclosure and you are relying on the moisture level in your substrate to help boost humidity levels, letting the soil dry out may reduce the risk of fungus gnats that love to lay the eggs in the moist soil. The drier conditions can stop the fly from laying the eggs.

10. Ongoing Maintenance

Once you’ve taken these steps, it’s essential to maintain strict hygiene protocols to prevent a recurrence.

  1. Regular cleaning: Clean the tank and replace the water regularly.
  2. Monitor the tank: Keep a close watch for signs of flies and take immediate action if you spot them.


Seeing fruit flies and fungus gnats in your crested reptile enclosure is very common because these flies get attracted to your reptile pet’s food. They are not dangerous to your reptile, but they are very irritating or frustrating. By using some of the useful methods, you may get rid of such flies.  

In my experience, using a KATCHY Indoor Insect Trap is the most effective solution to get rid of such flies quickly and effectively.

Filled under: Lizards

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