Do Fruit Flies Like Coffee Grounds?

Fruit flies are annoying on their own, but finding them in strange places – like buzzing around your coffee maker – can be frustrating and downright confusing.

So, do fruit flies like coffee grounds? Does a coffee buzz make them buzz?

Fruit flies are mainly attracted to:

  • Rotting foods 
  • Fresh products
  • Moist areas

However, they may be drawn to other, more unusual sources as well, including cat food… and coffee machines! 

If you find that fruit flies are swarming your coffee maker, then it’s natural to assume that the coffee grounds might be the culprit. But it may be left-over moisture rather than coffee grounds that attract them, unless your grounds have been there for a while.

In this article, we’ll take a look at whether fruit flies are attracted to coffee grounds, and some of the other things in your home that they may be drawn to. 

Why Fruit Flies May Like Your Coffee Machine

If you find congregations of fruit flies in your coffee machine or your coffee grounds, then there is certainly something they are attracted to! Of course, the last thing you want to do is take a sip of coffee that’s full of fruit flies!

But you’ll be happy to know that it’s probably not your coffee machine that’s the problem. 

However, there are some reasons why fruit flies might like your coffee machine.

Here they are:

1. Moisture

Fruit flies are drawn to moisture. So if you aren’t wiping your coffee machine down regularly, then it can become an attractive place for bugs.

After you’ve made a cup of joe, be sure to dispose of the used grounds immediately, and give the basket and any exposed wet areas a good wipe down. 

If you notice excess moisture, then you may have a leak or opening in your coffee machine. Luckily, that is easy to remedy, especially with a little DIY know-how. 

2. Heat

Warm surfaces and heat are also appealing to fruit flies. If you haven’t cleaned your coffee maker in a while, the heated residue will start to make the old grounds rancid. This produces a magnetic smell that fruit flies will swarm to. 

3. Old or Dirty Grounds

Some people prefer to store their used grounds to put in the compost later or to use in recipes. So, if you’re one to save your old coffee grounds in a container, you’ll want to make sure that it’s an airtight one.

Fruit flies are drawn to moist and decaying substances to breed and eat. They love to swarm around rotten fruit and food, but will happily inhabit drains and other food sources — anyplace they can provide food for their young.

So try to ensure that there’s as little rotting food exposed in the house as possible!

Common Causes of Fruit Fly Infestations

Though it’s not unheard of for fruit flies to swarm a coffee maker, that’s probably not the primary location that they’re infesting (unless you haven’t used your machine in a while).

Here are some common areas that may be causing your fruit fly problem:

1. A bowl of fruit

If you keep a bowl of fruit out in your kitchen, and you haven’t touched it for a while, then that may be drawing in the pests. 

If you keep a bowl of fruit out in your kitchen, then that may be drawing in the pests.

If you want to prevent an infestation, consider storing your fruit in a cupboard or refrigerator. You can also cover your fruit bowl with some sort of covering or simply transfer it into a sealed tub.

Just note that fruit flies can survive in the fridge for hours. And be sure to toss any rotten food before you put the remaining food in the fridge. The larva and eggs may well still be there!

2. Dirty sink

Dirty sinks and drains are perhaps the most common places for fruit flies to breed and live. Thankfully, they’re some of the easiest places to exterminate.

All you need is a dishcloth and some boiling water. Pour it down the drain regularly, and you’ll clear out any fruit flies or drain flies that have set up shop.

Note that some people recommend bleach, but it’s potentially hazardous to put bleach down the drains

Stick to boiling water.

3. House plants

Fruit flies (and fungus gnats) go crazy for many house plants. If you’ve got what appears to be an infested plant, move it into your garage or even outside if possible.

If, after you’ve done this, you notice a significant decrease in the number of fruit flies in your house, then you’ll know that they’re infesting your plant’s soil. 

Rather than tossing the plants out entirely, simply place a vinegar trap near them to kill the flies before they get a chance to ruin your flora. 

Getting Rid of Fruit Flies

Tired of fruit flies making your house a living nightmare? Here are some ways you can get rid of those pesky buzzers for good.

1. Remove any old fruit & vegetables

This is the first step that you should take in trying to deal with a fruit fly infestation. Start by getting rid of any fruits, vegetables, and other organic materials that are fermenting or rotting.

There is a high chance that the fruit flies in your home are using these substances as places to lay their eggs. And if you don’t get rid of them, then you won’t be able to get rid of the fruit flies!

Don’t just throw these items in the kitchen trash, bring them outside. They can often infest your trash can if you leave them in the kitchen, creating yet another problem.

2. Eliminate standing water

As we’ve already mentioned, fruit flies need moisture to breed. This is why it’s important to get rid of any sources of moisture or stagnant water in your house.

Some of the most common stagnant water sources include empty cans and bottles, ice machines, and the areas around your sinks and drains. 

Fruit flies need moisture to breed.

3. Create a vinegar trap

For smaller residential kitchens, home remedies can be more effective. One of the most popular home methods for getting rid of fruit flies is to create a vinegar trap, and the process is much easier than it may sound. 

  1. Start by placing a small amount of vinegar in the bottom of a container. Don’t use white vinegar – apple cider, red wine, or balsamic vinegar are the only ones that will work for this. 
  2. Add a generous amount of dish soap.
  3. Cover the top securely using plastic wrap or lid, then use an elastic band to keep the plastic in place over the opening of the container. 
  4. Poke several holes in the plastic. These holes should be large enough for the flies to enter.
  5. Then, place the trap in your kitchen and wait.

The fruit flies in your home will be drawn to the scent of the vinegar and will make their way into the container through the holes. They’ll touch the vinegar and promptly drown because of the dish soap.

Once you’ve caught enough flies, you can wash them down the drain and repeat this process until all of the flies in your home have been dealt with.


Fruit flies commonly infest the kitchen, and it can be difficult to figure out the ground zero of the infestation. While they can infest coffee machines, usually these machines are not their primary target.

They’re usually collateral damage.

Check your drains, pay attention to any rotten fruit, and check your trash and compost bins. These are the most likely areas of infestation. And be sure to regularly clean and wipe down your coffee machine to help keep fruit flies away.