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 tiny creature fly up out of the drain. Was that a gnat? Then you watch more of them buzzing around your kitchen. These annoying 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 survive 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 lured by moisture and rotten food, they’ll head for your trash can, your rotten fruit and the kitchen drain, which is full of moisture and small bits of food. Occasionally you’ll notice them come up out of the drain. This can be especially bad if you have a partially clogged sink or disposal that drains slowly. This preserves more moisture and food debris that draws 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 carry germs with them. This might include listeria, salmonella and even E. coli. All of these bacteria can cause severe cases of food poisoning. 

What Can I Do About Them? 

Owing to this bacterial risk, keep your surfaces clean at all times. Use a kitchen surface cleaner that eliminates 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 destroy the eggs. And you likely don’t want to spread insecticide all around your kitchen. Instead, put boiling water in your drain. Before bed, close off your drains with clear packing tape. In the morning, you should see some fruit flies stuck to it. 

Here are other barriers you can also attempt, all involving a jar: 

  • Wine—Pour an ounce of wine inside the jar. Add a hole in the lid so the fruit flies can enter. You can also have a funnel or paper cone instead of a lid. 
  • Rotten fruit—Same as above, but use rotten fruit rather than 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 minimize bringing in fruit flies: 

  • Wash your produce immediately after bringing it home. Occasionally they can contain fruit fly eggs or larvae. 
  • Refrigerate as soon as you can. 
  • Avoid keeping spoiled produce in your house. Buy only what you’re most likely to eat. 
  • Empty your kitchen trash often, and keep it closed. 
  • Keep your surfaces clean and disinfected. 
  • If you like to keep windows open, install well-fitted screens. 

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

You should also call a plumber if your kitchen sink or garbage disposal is draining more slowly than usual. This problem not only helps attract fruit flies, but over time the sink drain can entirely clog and become inoperable. The Service Experts Heating, Air Conditioning & Plumbing plumbing team has the tools, experience and know-how to identify the problem and solve it quickly. We employ a video drain inspector to clearly see what’s happening inside the pipes, and a number of methods to clean them, depending on the type and severity 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 need any sort of plumbing service at all, contact the professionals at Service Experts Heating, Air Conditioning & Plumbing. Whether we’re warming, cooling or making the water run, we take great pride in keeping our customers satisfied. 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. 

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