How do I keep rats out of my compost?

December 9, 2017 1:20 PM

Please describe your rat-proof compost bin solution.

I have one of those black plastic modular cube things with the stacking walls and the lid that folds open. Rats get in the bottom, even though it's sitting on a plastic base, the base is not attached to the body. I suspect they could squeeze in the cracks too. I have a few weeks off work and I am ready to make or buy a compost bin that reliably keeps rats out.

posted by latkes to Home & Garden (13 answers total)

I've always heard that you need to keep protein and fats out of the compost to deter rats. Only vegetation and plant-based products, like coffee grounds, parsley stems and celery leaves, should go into a compost. No meat, eggs, mixed food scraps, etc. Also, that compost should be mostly leaves and grass, and that kitchen waste should be a small percentage of the compost.

What are you putting in your compost?
posted by citygirl at 1:45 PM on December 9, 2017 [5 favorites]

We had rats getting into our compost bin that sat on the ground so we swapped it out for a tumbler-style bin, where it's up on metal legs, and that seems to have solved the problem. Not this one exactly, but similar: https://www.gardeners.com/buy/dual-batch-compost-tumbler/39-652.html
posted by little cow make small moo at 2:01 PM on December 9, 2017 [2 favorites]

Rats just chewed through my black plastic bin so I wrapped it in rabbit wire and that seemed to work. I suspect that they could have chewed through the lid too, but the top of the bin is a bit too exposed for their taste. There are owls and hawks in my neighbourhood.

My landlord's genius gardener took the wire and used it for something else. Now there's a rat freeway from my bin into the neighbour's yard and I don't really care. Not caring is always an option.
posted by klanawa at 2:12 PM on December 9, 2017 [2 favorites]

We tried the tumbler up on legs as suggested earlier and we didn't do any meats or fats. The rats still chewed through it.
We gave up on composting. Fortunately our city picks up green waste weekly.
posted by k8t at 4:44 PM on December 9, 2017 [1 favorite]

Don‘t do the tumbler - they easily chew through it. I‘m in a (rat infested) Bay Area lot and have tried tumbler and restricting the yummy foodstuffs like suggested above. But they are still attracted by fruit or non-green veg like carrots. And at that point, I can‘t use it because most of my kitchen scraps are fruit.

I want to try and use a galvanized bin that I drill holes in - will let you know how it goes.
posted by The Toad at 5:03 PM on December 9, 2017 [1 favorite]

I believe I heard that one solution is a metal trash can with tiny holes (like smaller-than-a-dime tiny) and a lid that you can strap down with a bungee cord... if I remember that right from the friends who was trying to figure it out.
posted by salvia at 6:51 PM on December 9, 2017 [2 favorites]

A second recommendation here for using rabbit wire. In response to a rat moving in, my partner rebuilt our box: the bottom and sides are now wood frames with rabbit wire for screening, and the top is covered with wood slats. No tunneling possible, no rat sightings so far (it's been maybe 3-4 months now).

I'll also add another data-point against plastic - our neighbors discovered a huge rat-chewed hole in the back of their plastic bin.
posted by marlys at 7:04 PM on December 9, 2017 [1 favorite]

Quick follow-up with an image for reference: our new bin looks a bit like this, but with no hinges (frames are attached directly to each other), and a solid wood cover (to keep out rat and rain - the top could be a hinged wood frame with rabbit wire instead if preferred).
posted by marlys at 7:14 PM on December 9, 2017

I was about to suggest this guy but uh it appears I do not have persistent rats.

I've heard good things about the thick metal trash can (not cheap aluminum!) with the bonus that some people say they can put it on its side and roll it to speed things up--though that requires a VERY tight lid and possibly multiple people when it gets full.
posted by Anonymous at 8:22 PM on December 9, 2017

Seconding salvia - I lived in New York City and did backyard compost in a metal trash can with holes in the sides and a tight fitting lid, like a much less fancy version of this, and rats didn't touch it.
posted by centrifugal at 12:12 AM on December 10, 2017 [1 favorite]

We stopped composting our kitchen scraps when we got our backyard chooks. They're quick and thorough, leaving nothing behind that rats could possibly use, and chook poo is the best fertilizer.

Bonuses: endless amusement watching them attend to their vital business with great seriousness, and the best eggs we've ever eaten.
posted by flabdablet at 3:49 AM on December 10, 2017

If the environment is suitable, go to your local animal rescue and take responsibility for a cat. Give the cat unrestricted access to the composting area.

Select the cat wisely. You want a hunter. Size is a bonus (although the best ratting cat I ever had was tiny - scarcely larger than a well-fed rat herself.) Queens tend to be better than toms. I've often found that tabbys are more focused than other colourings, but cat genetics is utterly stuffed up these days. Look into her eyes. You should feel fear. A real hunter makes herself known.

If you have the time and attention, a terrier is an option. They will happily kill rats all day long. If you live in a rural area, you probably have a friend with a ratter. Borrow it for a few hours. The surviving rats will get the message.

Using cats, dogs or other tame animals for pest control comes with huge responsibility. Check your hunter for injuries every day. Make sure they are vaccinated properly. Carry vet insurance.

I grew up in a very rural area. There were rats around. The cats and the sheepdogs meant we rarely saw a live one.

Otherwise, metal chickenwire and three-dimensional thinking is your only option, and the rats are smarter and more patient than you in matters related to compost.
posted by Combat Wombat at 6:23 AM on December 11, 2017

Response by poster: I used the metal trash can solution. Drilled holes in the bottom and holding the lid on with a bunjee. It's a little funky in there - the wet to dry ratios are different in a more sealed environment, but overall, working great. Thanks!
posted by latkes at 7:54 PM on February 20, 2018 [1 favorite]