Why Are There Fruit Flies in My Kitchen Sink Drain?

Has this ever happened to you? You’re cleaning a dish in the kitchen sink and watch a small creature shoot up out of the drain. Was that a gnat? Then you watch more of them zooming around your kitchen. These aggravating little guys are actually fruit flies. And if you’re asking how they got in there and what may be done about them, you’re in the right place.

Why Are They Here?

Fruit flies survive all over the U.S., and mate quickly. According to WebMD, “An adult female fruit fly can lay up to 2,000 eggs on the surface of anything that's moist and rotting. Within 30 hours, tiny maggots hatch and start to eat the decayed food. Within two days, they're all grown up and ready to mate.” As they’re attracted to moisture and rotting food, they’ll frequently appear in your trash can, your rotten fruit and the kitchen drain, which is packed with moisture and tiny pieces of food. Occasionally you’ll watch them fly up out of the drain. This can be notably bad if you have a partially clogged sink or disposal that drains slowly. This maintains more moisture and food debris that draws these insects and enables them to thrive and reproduce.

How Bad Are They?

When fruit flies transfer from a dirty surface to a clean one, they bring germs with them. This may include listeria, salmonella and even E. coli. All of these bacteria can result in severe cases of food poisoning.

What Can I Do About Them?

Because of this bacterial risk, keep your home's surfaces clean at all times. Use a kitchen surface cleaner that eliminates bacteria. Don’t reuse sponges that can absorb, retain and transfer germs. It’s cleaner to use paper towels and dispose of them.

Bug sprays can eliminate the adult fruit flies but won’t destroy the eggs. And you probably don’t want to spread insecticide all around your kitchen. Instead, put boiling water in your drain. Before bed, block off your drains with clear packing tape. Each morning, you ought to see some fruit flies attached to it.

Here are other traps you can also use, all involving a jar:

  • Wine—Place an ounce of wine in the jar. Make a hole in the lid so the fruit flies can enter. You can also have a funnel or paper cone rather than a lid.
  • Spoiled fruit—Same as above, but with rotten fruit instead of wine.
  • Apple cider vinegar—Same as above but with apple cider vinegar.
  • Apple cider vinegar and dish soap—Same as above with dish liquid in addition, which makes it much harder for flies to get away.
  • Yeast—Pour in two or three ounces of water, one packet of activated dry yeast and a teaspoon of sugar.

To prevent bringing in fruit flies:

  • Rinse your produce as soon you bring it home. Sometimes they can contain fruit fly eggs or larvae.
  • Refrigerate as soon as you can.
  • Don't keep spoiled produce in your home. Buy only what you’re going to eat.
  • Empty your kitchen trash often, and keep it closed.
  • Keep your surfaces clean and disinfected.
  • If you prefer to keep windows raised, install well-fitted screens.

If the above methods haven’t resolved your fruit fly issue, there could also be an issue with your p-trap. That’s the area of your drain pipe bent in a u shape to capture water and keep foul air from drifting up into your home. It also keeps flies from surviving in your pipes and flying up out of the drain. If your pipe has a leak and lacks a water seal, this can create a fruit fly problem. Run the water and check below for a leak. If you see one, get it fixed quickly. Leaky pipes can encourage mold and structural damage to your home.

You should also contact a plumber if your kitchen sink or garbage disposal is draining slowly. This problem not only helps attract fruit flies, but over time the sink drain can completely clog and become unusable. The Service Experts Heating & Air Conditioning plumbing team has the equipment, experience and know-how to identify the problem and fix it quickly. We utilize a video drain inspector to clearly see what’s going on inside the pipes, and a number of methods to clean them, depending on the type and extent of the blockage. If the problem is your garbage disposal, we can repair or replace it at a price you can afford. We also clear leaky pipes.

If you are looking for any sort of plumbing service at all, call the professionals at Service Experts Heating & Air Conditioning. Whether we’re warming, cooling or making the water run, we take great pride in keeping our customers comfortable. With more than 4,000 team members, we can deliver and innovate better than anyone. Our can-do family attitude helps us get the job done on time, and right—the first time.