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 notice a small creature shoot up out of the drain. Was that a gnat? Then you notice more of them zooming around the kitchen. These aggravating little guys are actually fruit flies. And if you’re wondering 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.” Because they’re lured by moisture and rotten food, they’ll head for your trash can, your rotten fruit and the kitchen drain, which is packed with moisture and small pieces of food. In some cases you’ll watch them fly up out of the drain. This can be especially likely if you have a partially clogged sink or disposal that empties slowly. This preserves more moisture and food particles 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 bring germs with them. This may include listeria, salmonella and even E. coli. All of these bacteria can cause serious cases of food poisoning. 

What Can I Do About Them? 

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

Bug sprays can eliminate the adult fruit flies but won’t get rid of the eggs. And you likely don’t want to spread insecticide all around your kitchen. Instead, pour boiling water into your drain. Before bed, close off your drains with clear packing tape. Each morning, you can see some fruit flies attached to it. 

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

• Wine—Place an ounce of wine into the jar. Put a hole in the lid so the fruit flies can get in. You can also use a funnel or paper cone instead of a lid. 

• Rotten fruit—Same as above, but use rotten fruit instead of wine. 
• Apple cider vinegar—Same as above but using apple cider vinegar. 
• Apple cider vinegar and dish soap—Same as above with dish liquid added, which makes it much harder for flies to break free. 
• Yeast—Add two or three ounces of water, one packet of activated dry yeast along with a teaspoon of sugar. 

To prevent encouraging fruit flies: 

• Clean your produce immediately after bringing it home. In some cases they can possess fruit fly eggs or larvae. 
• Refrigerate whatever you can. 
• Avoid keeping spoiled produce in your house. 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, put in some well-fitted screens. 

If the above methods haven’t eliminated your fruit fly problem, there could also be a problem with your p-trap. That’s the part of your drain pipe bent in a u shape to capture water and prevent foul air from drifting up into your home. It also prevents flies from surviving in your pipes and flying up out of the drain. If your pipe has a leak and has no water seal, this can create a fruit fly problem. Run the water and check below for a leak. If you spot one, get it fixed quickly. Leaky pipes can lead to mold and structural damage to 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 attract fruit flies, but over time the sink drain can entirely clog and become unusable. The Service Experts Heating, Air Conditioning & Plumbing plumbing team has the tools, experience and know-how to diagnose the problem and fix it right away. We use a video drain inspector to plainly see what’s going on within the pipes, and a number of methods to clean them, depending on the type and extent of the blockage. If the problem is a 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 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.