How to Get Rid of Fruit Flies in a Worm Compost Bin
Fruit flies are such a pain to get rid of once they’re in your house but what do you do if your vermicomposting worm bin has fruit flies? Sure we could always keep the worm bin outside, but when the temperatures are in the upper 90’s outside the poor worms will cook in our worm bin. We thought about putting the worm bin in the shop or barn, but those two places also get pretty warm when the temperatures soar. Our last resort was putting them in the house. But before they moved into the house, we needed to get rid of those pesky fruit flies!
When we got our first worm bin last month, we kept it on the back porch. Every time I took the lid off, a bunch of fruit flies would escape. Not what we want to have happening in the house! If you missed this post, I mentioned we bought our worm bin from someone on Craigslist. I’ve been learning quite a bit about vermicomposting in the last month, especially about fruit flies in worm bins.
I did a bunch of research and asked some other vermicomposters how they get rid of fruit flies in their worm bins. A lot of people keep their worm bins in the house, and quite a few told me they keep them in the kitchen! So there had to be a way to keep the fruit flies away. A bunch of folks told me they decided to not feed their worms fruit and vegetable kitchen scraps so they wouldn’t have issues with fruit flies. I started vermicomposting with the intent of feeding the worms kitchen scraps so this wasn’t going to work for us!
Three Key Elements to Get Rid of Fruit Flies in a Worm Compost Bin
I eventually discovered three key elements to keep fruit flies out of the worm composting bin while still feeding them fruit and vegetable scraps. I’ve been doing these two things for a couple weeks now and we no longer have issues with fruit flies! What does that mean? Our worms now live in the house, in a nice shady corner of the laundry room.
#1: Freeze all worm “food” before adding it to the bin.
Fruit flies lay their eggs on the skin of produce. When frozen, the eggs are killed. We now keep a gallon size plastic bag in the freezer and add produce scraps to it as we have them. Once the bag is full, I keep it in the freezer for another 24 hours just to make sure the last batch of scraps added to it have a chance to fully freeze.
After freezing the produce scraps for at least 24 hours, remove them from the freezer. Let them thaw and return to room temperature. Then they are ready to be fed to your worms. After the produce is frozen and then thawed, it all starts to turn in to a slimy mess which the worms love even more!
#2: Bury the food in the worm bin.
Instead of laying the produce scraps on top of the other materials in the bin, bury them. I keep a small hand rake by the worm bin so when I feed them I can use it to carefully rake the other materials back and bury the new food. The idea behind burying the food is that it keeps it out of reach to any flying insects, like fruit flies, that may happen to sneak into your bin. If they can’t reach it, they won’t lay eggs in it.
#3: Put damp newspaper scraps on the top layer of the compost bin.
We tore newspaper into thin 1/2″-1″ wide strips and laid it on top of the other layers of material in our worm bin. If you tear with the grain of the paper, you will be amazed at how easily it tears in nice uniform strips! Place enough newspaper strips on top so you can’t see the next layer underneath. Again the idea with this is to keep the soil layer or any food scraps poking up through inaccessible to the fruit flies to lay eggs.
Spritz water on the newspaper strips until they are damp. This is another great way to gauge the moisture level in the worm bin. For a newbie vermicomposter, trying to figure out if the bin is wet enough or too wet can be tricky. The newspaper is an easy gauge. When you check the worm bin and the newspaper is dried out, sprtiz it with water until it is damp again. If the newspaper is soaking wet, it is probably a little too wet in the bin and the lid needs to stay off for a bit. We’ve also noticed that the worms loved to eat the newspaper layer so eventually you will need to add more as they consume it.
Last month I was at a loss on how to get rid of the fruit flies in our worm bin. Now that I know how to keep fruit flies out of the worm compost bin we’ve been fruit fly free! These three simple steps made all the difference in the world for us. Our worms are now happily living in their bin in a cool part of the house. They’re consuming our kitchen scraps and making us compost without a fruit fly infestation in the house!
Have you ever had fruit flies in your vermicomposting worm bin? Do you have any tips to share?
This post shared on: From the Farm Blog Hop, Old Fashioned Friday,
You shouldn’t have to freeze the scraps. Just covering them is enough. Also, never let the paper get dry. The worms can’t eat it dry. As long as it stays wet, the worms will lay their eggs in it. Once you have an explosion (hatching) of worms, the babies really need the paper. In case you didn’t know, the eggs look like grains of rice.
We tried it without freezing the scraps and still had fruit flies. Once we added in that step, we haven’t had any issues. That’s great you don’t have to freeze your food scraps, for some reason not freezing them didn’t work for us. Thank you for sharing that great tip about always keeping the newspaper damp/wet so the worms can eat it!
Thanks for the article. I follow method as you with great results. The only problem I have is that I had a couple peaches that were past ripe and mashed them up and added them to my normal feeding. It looks like I got these fruit flies from the peaches. I read you article based on the title but I didn’t see any advice on how to get rid of the fruit flies. Have been using apple cider vinegar with a few drop a Dawn dish soap in a bowl to attract and drown them but looking for a faster method. Any ideas?
I started our worms around the same time frame as you I beleive (Mothers Day weekend here) Mine started off in the unused dinning room and then got relocated to the basement as the days got hotter. I too had those nasty little flies. Not sure why as I was burying the foor, keeping it covered with damp newspaper. The way I solved the problem was I wet a large towel, wrung it out pretty well and covered our bin. The flies got trapped in the towel texture and died I guess. I try to keep the towel damp. We simple have no more flies! Yeah! Our worms are growing and they should be doubling in an other 4-6 weeks. (I guess the worms double the number in about 3 months) I started with 250 so 500, then 1000, then 2000 by the first year. I am hoping for 4000 so I have a ways to go.
That’s a great tip about the damp towel, thank you for sharing that! That’s a pretty easy way to make sure no fruit flies escape from the bin.
Does the damp towel go inside the bin, or draped over the outside?
Reading your post made me realize I needed to add more newspaper to my own bin.
As for the fly problem, My solution was self implemented… I have a small spider living in my bin eating the flies! Since he moved in I have not seen a single fly nor lost a worm. As soon as the flies move in to the bin Mr. Spider orders dinner.
I love it, an all natural fruit fly trap!!
You can try a fruit fly trap. Easy to make and it works. If you are interested.
I’ve heard making fruit fly traps are pretty easy. We’re hoping we won’t need one since we haven’t had issues lately. Fingers crossed we don’t need to make one 🙂
This is why I have stopped vermicomposting…darn fruit flies. I too buried new food, did the newspaper, but I didn’t try the freezing of the food. I miss my worms but until I can solve the fruit fly problem I can’t have them in the house. What is the ideal temperature they (worms) should be raised in? Could my basement be too warm? Could that cause the fruit fly explosion?
I initially had tried burying the food but not freezing it and that did not work for us. Once we started freezing the food scraps, we stopped having fruit fly issues. Worm bins do best with temperatures 55 degrees to 75 degrees fahrenheit. Basements are usually cooler than the rest of the house and an ideal spot for worm bins. Unfortunately we don’t have a basement so our bin is in the laundry/mud room where it stays in the 70’s during the day in the summer. Another comment on this post, from Rachelle, mentioned she put a damp towel over top the worm bin and the fruit flies got caught in it and couldn’t escape. Maybe that is an idea you could try if you ever venture into vermicomposting again!
I stopped also because of the flies. Miss my worms also.
Okay, I’m not sure *why* I hadn’t considered fruit flies as a potential vermicomposting problem… but I hadn’t. These are all great suggestions… but I think I’ll wait until the weather gets cooler before starting one in our basement! 😉
~ Christine
Those are great suggestions! I will start to freeze my scraps too. Hopefully it will help since those flies are awful. I linked your post to my own post about how we saved a frozen worm composting bin my husband found outdoors a few weeks ago. Thanks!
Thanks Lee! I checked out your post on worms and I’m so amazed that you were able to save it and have all those worms hatch!!!!
And if some of those pesky pests thwart your best efforts? Get a Sundew! I have Drosera capensis growing in bog-like conditions under a bright growlight. The critters seem to be attracted to the sticky “dewdrops” more than anything ripening on the kitchen counter. And kids are fascinated by this very different kind of carnivore!
Very nice article; well written and great photos.
One other thing that happens when you freeze fruits & veggies is their cell walls can rupture. This is a good thing since it accelerates decomposition and bioavailability of nutrients to the worms.
Keep up the great work!
Hv tried the apple cider vinegar in the bottle method to trap the fruit flies. I put the bottle in the worm compost bin last night. Checked today morning, no flies have been trapped. How long should I wait? When would results be seen? I plan to microwave the fruit and veg peels before tossing them into the bin. As for burying the scraps in the compost, I have just started the worm bin, and the bedding is not very thick.
Any help?
I just started my vermicomposting yesterday thank you very much for the tips
Thank you for this wonderful post. I JUST started my worm bins 2 days ago in my basement and this morning I found gnats and fruit flies. I don’t know why I never considered them to be a problem when I was setting up my bin. . There were many great tips suggested and I will certainly try a few of them today before I get over run with insects.
I’ve had my worms for about 4 months now and my struggle has been with fungus flies, (drain flies). I feed chicken mashed and add wild carrots when the ground is not to frozen to pull them. The wild carrots get ground up for faster breakdown and added. The problem with these invaters is they lay there eggs in the damp substrate and letting my bed dry out doesn’t seem to be a good option. any ideas from my fellow farmers?
Hi, I have had issue with worm escape (250) and with foreign invaders I started over with clean bedding since I found my first issue was my bins were too wet. I didn’t throw out the bad mix, I just buried it in a garden bed and nature will work it out. My new mixture is a combo of peat, compost-chicken and cow. I also added vermiculite and Dolomite (not garden lime). I m also feeding with a worm chow I make out of coffee grounds, egg shells, chicken feed, oatmeal and a little brewers yeast. I cover with paper and card board. So far so good. Later I will incorporate kitchen scraps but less water. I live alone so the scraps are minimal and neighbors scrap are unpredictable.