Drain Fly Larvae In Toilet: 5 Removal Tactics

If you’ve noticed drain fly larvae in your toilet, you’ve found the right article. In this article, not only will you find out why there are drain fly larvae in your toilet in the first place, but you’ll also learn how to get rid of them, and how to prevent them from coming back again!

So keep reading to find out everything you need to know about dealing with drain fly larvae in your toilet!

What Are Drain Fly Larvae?

Drain fly larvae are the immature stage of drain flies. They are a similar size to gnats and fruit flies -1/4 inch to 1/2 inch long- and are identified by their tiny, moth-like wings and round, fuzzy bodies.

These little creatures tend to hop rather than fly. They have a lifespan of eight to twenty-four days, and the female can lay around three hundred eggs in forty-eight hours.

How Do I Check If I Have Drain Fly Larvae?

Use the following checklist to determine whether you’re dealing with an infestation.

  • Flies lay their eggs in clogged sinks, tubs, and toilets. Check the toilet bowl regularly (every week or two) after use; if there are traces of human waste or tissue paper, drain fly larvae could also be present. If you suspect a drain fly infestation, using a torch, inspect your drains by looking for larvae or adult flies.
  • Drain flies lay their eggs in garbage disposals and drains where there is rotting food or other organic material. When they hatch, they go through a series of stages as they mature. The final stage of their life cycle is when they become adults and mate before dying off within a few days after hatching from the larvae. These eggs produce the odor you smell as they grow into adults within your plumbing system.
  • Check around the rim of your toilet bowl. That’s where the flies lay their eggs. If you find any eggs, remove them immediately with a cloth or wire brush and flush them — they can cause problems if they hatch and start growing inside the toilet.
  • If you are unsure whether you have a drain fly infestation with a flashlight, check the sides of your outside drains for thin, tube-like larvae. If you don’t find any here but are sure there is an infestation, this could mean that the eggs have been laid deeper within your pipes.

Why Are There Drain Fly Larvae In Your Toilet?

If you find drain fly larvae in your toilet, it means that drain flies are breeding somewhere close by. The chances are the seal between the sewer flange and toilet has been broken, and drain flies have begun breeding there.

However, there are occasions when they could be breeding in the toilet’s tank, or inside the rim, especially when the toilet hasn’t been in use for a while!

The reason that drain flies love these areas so much is because they’re humid, moist, and provide an abundance of organic matter for themselves and their larvae to feed on!

How Do You Get Rid Of Drain Fly Larvae In Your Toilet?

Fortunately, removing drain fly larvae from your toilet isn’t actually too difficult. And there are a few natural and chemical methods you can try to get rid of them!

Scrub The Toilet With Bleach

One of the easiest ways to try and remove drain fly larvae from your toilet is to scrub around the bowl and under the rim with bleach. Any larvae or eggs that come into contact with the bleach will die.

However, this isn’t a one-and-done situation. You should scrub your toilet with bleach every day for a couple of weeks to make sure you’re permanently removing drain flies!

Baking Soda And Vinegar

Another method you can try is baking soda and vinegar. This is one great way at removing any build-up of grime from the pipes themselves, as well as the larvae too!

To use baking soda and vinegar, you should start by scooping out some of the water from the bowl. Once the bowl is about halfway full with water, you can then add one cup of baking soda to the bowl.

Then all you have to do is pour a cup of vinegar into the bowl as well. Make sure you do this slowly so that the reaction doesn’t make a mess.

Now all you have to do is wait 20 minutes, before flushing the chain.

Drain Cleaner

Caution should be used when trying drain cleaner because a lot of them are going to do more harm than good in your toilet. However, one drain cleaner that you can use in your toilets is Green Gobbler Ultimate Main Drain Opener.

Just make sure when you’re using it to follow the instructions provided, otherwise, you may end up damaging your toilet.

Remove Them From The Water Storage Tank

If you notice that drain fly laevae have taken up residence in your water tank, there are a few things you can do to ensure that they leave.

  • To begin, turn off the shutoff valve found at the rear of the toilet. If you have trouble finding it look for a metal oval attached to a hose.
  • You can now flush your toilet which will flush the water out of the tank. If flushing does not remove all of the water, you can pull the chain in the tank, which will lift the flapper and remove the remaining water.
  • The inside of the tank should now be completely dry. During this time, keep an eye out for drain fly eggs and larvae that need to be removed.
  • The next step is to make sure the drain flies and their larvae don’t return. The best method to do this is to use an insect growth regulator. Gentrol Aerosol Insect Growth Regulator is a good option, as it only needs to be sprayed about the tank.
  • You can turn the water back on and allow the tank to fill once the IGR has dried entirely. Just make sure you rinse it out multiple times.
  • Finally, after you’ve finished, add a bleach pill to the tank to assist in eradicating any drain flies that may be hiding in other places of your toilet.

Removing Drain Fly Larvae From The Closet Flange

Getting rid of drain flies from the closet flange is one of the most difficult parts, and it can also be rather costly if done incorrectly. You’ll need to do the following to get rid of them:

  • Turn off the water in your toilet and flush until there is no more water in the tank or bowl.
  • Unscrew the bolts that hold the tank to the bowl.
  • Remove the bolts holding the toilet bowl to the floor.
  • After that, you can move the bowl to gain access to the closet flange. To make sure you don’t pull the water hose out, make sure you do this with are.
  • Now that you’ve gained access to the closet flange, clean it well to remove any mold or sludge that could be attracting drain flies. (A paint scraper is very useful for removing any eggs that may have become stuck to the sidewalls.)
  • After you’ve finished cleaning the pipe thoroughly, pour half a gallon of boiling water into it to kill any larvae that come into contact with it. Natural Armor Fruit And Drain Fly Killer can also be used for optimal results.
  • After that, all you have to do is reassemble everything and flush the chain a few times to ensure everything is working properly.

How To Stop Drain Flies From Entering Your Home

Now you know how to get rid of drain flies from your toilet, here are all the ways you can prevent them from entering your home in the future as well!

Make Sure You’re Flushing Your Toilet & Pipes Regularly

One of the best things you can do is make sure you’re flushing your toilet and pipes regularly. This way standing water won’t be allowed to stagnate for as long, as this is one of the main attractions for drain flies in your home!

Look For Stagnant Water Near Your Home

You should also look for stagnant water near your home as well. Drain flies tend to come from outside your home and then migrate inwards. So if you can remove their habitat outside, they’ll move further away from your house to survive.

Make Sure You’re Cleaning Thoroughly

And you need to make sure you’re cleaning every area of your home thoroughly, especially the areas where you know organic debris or standing water can accumulate. This is one of the best things you can do to stop drain flies from living in your home!

Can Drain Flies Live In Toilets?

Yes, they can! They are not just living there but breeding.

They feed on the fluids exuded by hair, skin, and other organic material. The uric acid smell, the byproduct of urine, is also an attraction to these moth flies. It can pool in your toilet bowl and attract them to hibernate. The toilet itself is not a perfect environment for these insects to breed.

They are also attracted to light and often come out at night or when you turn on the bathroom light. They might seem harmless, but they threaten the health of you and your family. If you see any bugs in your toilet or sink, ensure you get rid of them immediately by flushing them.


Now you know how to remove drain fly larvae from your toilet, here are some frequently asked questions people have about drain fly larvae!

Does Bleach Kill Drain Fly Larvae?

If bleach comes into contact with drain flies, then it’s enough to kill them. However, it’s important to remember, that you’ll need to use bleach multiple times to get the best results. Only flushing your pipes or toilet with bleach once won’t be enough to remove all the drain flies.

Can Drain Flies Come From The Toilet?

It’s not likely that drain flies have come up from your toilet, but more likely that they found a part of your toilet that was already damaged, and then bred inside it.

What Do Drain Fly Larvae Look Like?

Drain fly larvae look like small black worms. And they are quite small (no more than 1cm in length)

Are Drain Fly Larvae Harmful?

They do not bite or transmit disease to humans, but they can cause asthma in some people, and the larvae can lead to myiasis, an infection in which the larvae actually grow inside human tissue like muscle or skin.

Can Drain Fly Larvae Be a Sign of an Underlying Plumbing Issue?

If you have a drain fly infestation, it’s important to know that they are not a sign of an underlying plumbing issue. In fact, the presence of the larvae itself is often the problem.


As you can see, if you have drain fly larvae in your toilet, you don’t need to worry too much. In most cases, they’re not going to be hard to remove! And with a few simple practices, you can also prevent them from returning!

If you liked this article, make sure you check out the rest of the website! Otherwise, have a great day!

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