Why Are There Fruit Flies in My Kitchen Sink Drain?

Has this ever happened to you? You’re washing a dish in the kitchen sink and see a small creature shoot up out of the drain. Is that a gnat? Then you watch more of them flying around your kitchen. These aggravating little guys are actually fruit flies. And if you’re wanting to know how they got in there and what you can do about them, you’re in the right place.

Why Are They Here?

Fruit flies live all over the U.S., and spread 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.” Since they’re drawn to moisture and decomposing food, they’ll head for your trash can, your overripe fruit and the kitchen drain, which is filled with moisture and small bits of food. Occasionally you’ll watch them come up out of the drain. This can be notably likely if you have a somewhat clogged sink or disposal that drains slowly. This preserves more moisture and food debris that attracts these insects and enables them to thrive and reproduce.

How Bad Are They?

When fruit flies move 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 lead to severe cases of food poisoning.

What Can I Do About Them?

Due to this bacterial risk, keep your home's surfaces clean at all times. Use a kitchen surface cleaner that kills bacteria. Don’t reuse sponges that can attract, retain and exchange germs. It’s better to use paper towels and throw them away.

Bug sprays can kill off the adult fruit flies but won’t get rid of the eggs. And you most likely don’t want to apply insecticide all over your kitchen. Instead, put boiling water into your drain. Before bed, close up your drains with clear packing tape. Every morning, you should see some fruit flies trapped to it.

Here are other barriers you can also use, all with a jar:

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

To prevent bringing in fruit flies:

• Rinse your produce as soon you bring it home. In some cases they can have fruit fly eggs or larvae.
• Refrigerate whatever you can.
• Don't keep old produce in your kitchen. Buy only what you’re likely to eat.
• Empty your kitchen trash often, and keep it closed.
• Keep your surfaces clean and disinfected.
• If you prefer to keep windows open, put in some well-fitted screens.

If the above methods haven’t resolved your fruit fly issue, there may be something wrong with your p-trap. That’s the area of your drain pipe bent in a u shape to trap water and prevent foul air from moving up into your home. It also stops flies from hiding in your pipes and flying up out of the drain. If your pipe has a leak and has no water seal, this can produce a fruit fly infestation. Run the water and look below for a leak. If you find one, get it fixed promptly. Leaky pipes can encourage mold and structural problems with your home.

You should also contact a plumber if your kitchen sink or garbage disposal is draining more slowly than usual. This problem not only helps breed fruit flies, but over time the sink drain can completely clog and become useless. The Aramendia Plumbing, Heating and Air plumbing team has the equipment, experience and knowledge to identify the problem and solve it quickly. We use a video drain inspector to obviously 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 fix leaky pipes.

If you want any sort of plumbing service at all, get in touch with the professionals at Aramendia Plumbing, Heating and Air. 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.