On rats
Finally! Tackling the biggest and scariest of all compost questions.
We have rats at the community garden.
I’ve never had a problem with rats. I think they’re cute and I kept them as pets growing up. But working in compost has forced me to acknowledge that other people, by a large margin, do not like rats, and also that rats do pose certain risks (disease, electrical failures) that are reasonable to take seriously. So, I’ve learned that I need to figure out a way to talk to people about them. I also had to come up with a game plan to manage the rats out of our bins.
In general, rats want two things in life: shelter and vittles.
That means they tend to set up shop if they can find a place to hide that’s near a regular food supply. In our garden, that “place to hide” was a mulch pile that had grown to absurdly feral proportions over the course of the summer. The “regular food supply” was our compost. We had to fix both things. First, we cleared the mulch pile. Instead of leaving it heaped up near the bins, we spread it out over the garden. We also cleared out stacks of leftover cardboard and a set of old buckets filled with plastic trash. Then we weeded. Anything, including tall grasses, that could offer coverage to a marauding rat, we eliminated.
“Fixing” the compost was trickier. We weren’t going to stop putting food in, but I realized we could be less lazy about storing food scraps that were waiting to be added. Our usual system called for leaving soggy boxes of rotting food by the bins for sometimes a week at a time. We changed this to keeping everything secured in sealed, 5-gallon buckets. We then covered the open piles with a thicker layer of high-carbon materials (mostly sawdust), hoping to thoroughly smother any rat-enticing odors. After that we waited, hoping that the rats would realize the area was no longer ideally habitable and move on.
They did not.
Yesterday, I walked in the front gate only to have a rat run right over my foot and up my leg on its way into a nearby hole.
C’est la vie.
The fact is, there is simply no way to guarantee that an outdoor compost pile will never attract an animal. Not that I haven’t seen many composters try. They construct bins from sturdy material and heavy lids, then load them up with locks. They layer chicken wire. They brainstorm and deploy all kinds of other design tricks. Mostly, though, they only succeed in making their compost that much more difficult for themselves. Animals always seem to figure it out.
I guess that part of becoming a composter is accepting this.
You are going to get a skunk or a raccoon from time-to-time. They’ll come in and dig around a bit and disappear again. You also might come out one day to find a rat (or seven) making a home in the upper layers of your heap. That’s just part of sharing the world with other creatures. You will better serve your sanity if you can think of it as a relationship to manage versus a threat you are destined to fail at eliminating.
In general, though, thoughtful pile management will always be your best defense. Taking consistently good care of your pile means you will attract minimal interest from animals. The reason rats showed up in our garden is because I had fallen embarrassingly behind on basic maintenance. It happens.
They’ll leave soon, now.
Now that I’ve closed the welcome gate on a free meal and a nice hotel, they’ll move on in search of another place. It’ll just take some time. And they won’t likely come back if we continue to maintain a standard for our piles.
What choices you make with your compost will depend on what animals are in your area, of course, in addition to your own comfort levels with their existence in proximity to your home. If you live in a city, like me, you’re probably going to get rats, like I did. If you live in the woods, bears might be an issue. Bears are probably a greater concern than rats, on the whole.
But these are some general guidelines for keeping your pile animal proof-(ish):
• Take time to prepare your food scraps
You want to minimize the time that food scraps are sitting around in your pile, so anything you can do to expedite decomposition helps. Chop and shred things into the tiniest possible pieces, first. Stuff that’s already small? Cut it a little smaller. On that note, and I wish I didn’t have to say this so much, but I do: do not throw whole food items into your compost, if you are trying to avoid attracting animals.
• Cover your food scraps
Do not leave food scraps exposed, ever. Bury them in the pile. You might also employ a “biocap,” which is a thick layer of high-carbon material like sawdust, straw, or wood chips. You might want to do this in addition to having an actual, physical lid on your bin. It just helps reduce odors, which are the primary thing alerting animal’s to the presence of the pile. In general, do not leave food scraps sitting around, like I did.
• Restrict your materials
If animals, particularly bears, are a big problem in your area, there are some food types that you simply want to avoid composting altogether. Cooked food, meat, skins, oils, fats, and dairy are all on that list.
• Get to know your local critters
Familiarizing yourself with the preferences of the creatures that might raid your compost can help you build more strategic deterrence systems. Most animals are prone to sneaking. They look for regular food sources in low disturbance areas where they can also find places to shelter. Therefore, keeping the area around your compost clear of debris, piles of mulch, tall grasses, or any other potential hideouts can help dissuade them from setting up shop. Other animals dislike certain odors or food types. I’ve heard that orange peels and dog fur both act as deterrents for skunks, although I’ve never officially tested either hypothesis.
• Keep the area clear of piled debris and tall grasses
Just don’t give ‘em a spot to hide out. Don’t do it!
• Put bad smells to use
The odor of food may attract animals, but there are other odors that can deter. The Vermont Fish & Wildlife department recommends leaving an ammonia-soaked rag in a bucket near your compost in order to discourage bears from investigating things. Refresh every 2-3 weeks.
• Build your bin on a barrier
The above tactics may be sufficient to manage your critter issues. However, there is one high-effort intervention that may be worth it if you live in a particularly creature-dense region. You can build your compost on a solid base, like a concrete pad or a wooden deck that is raised an inch or so off the ground. This will ensure creatures cannot burrow in from below, which is one of the sneakier ways they will find their way into your pile.
I’ll end on a final note:
One memorable time, somebody asked me how they might rat-proof their compost because their wife “didn’t like rats.” I gave some boilerplate advice, like “cover the pile” and “just don’t leave food out”—but also acknowledged rats make their own, unpredictable choices and this guy and his wife might end up with a couple of them, anyway. He went on to describe his wife’s aversion (“she loses sleep thinking about them” “nightmares”) and I stopped him, laughing a bit. His wife didn’t just “dislike” rats. She had a full-blown phobia. I advised that he not torture her with an at-home system and instead take advantage of city-provided curbside composting.
So just a reminder that you, also, of course, always have options.
Love,
Cass
I think I saw a shrew around my pile this summer! My partner said they saw something that looked like a beaver in the garden too, which i am thinking was probably a groundhog, bc we don’t live close enough to water. I like when the animals come around, it feels like a good sign to me. I haven’t had the time/energy to harvest anything I planted this year so at least somebody’s eating it lol