Are there pests in your neighborhood? You may not even be aware of any small creatures like raccoons, mice, rats or insects in your midst until you start to compost. Previously unnoticed pests may now be looking for a new source of food or a cozy bed in your compost pile. It is important to note that composting will not encourage pest populations to move into your area, though a neglected pile may attract local populations and make them more visible to you. Studies have shown that pests, including rats, were the third most common composting obstacle—following lack of space and lack of knowledge. Pest problems should not be underestimated, but there are a few simple measures that can help to keep pests from getting in or being interested in your compost pile. The best solution is prevention!
Pest-proofing your bin can prevent animals from tunneling up through the bottom, climbing into the bin from the sides or top, or chewing holes in the bin. Below are some tips:
- Use hardware cloth to line the bottom and outside walls of your bin. For mice, 0.5 cm (1/4 in), 16 gauge should be used; 1 cm (1/2 in), 20 gauge for keeping out larger pests. (Hardware cloth is galvanized wire mesh, available at most home improvement/hardware stores. Chicken wire is not a good protection against unwanted visitors).
- Get a tight-fitting lid or modify your existing lid by adding hinges and a latch. Or stretch a bungee cord or chain across the lid and fasten it to the sides of the bin. A heavy brick or rock will also keep the lid secure.
- Pile rocks or bricks around the outside bottom edge of your bin as a good measure against burrowing animals.
- Alternatively, you could consider purchasing a rodent-proof bin that is already fitted with such deterrents.
Covering all food scraps is your best defense! When adding food scraps, dig a hole in the center of the pile. Then, add alternating layers of nitrogen and carbon (aka Lasagna Composting), always ending with a carbon layer, which serves as a blanket and keeps flies from laying eggs on the exposed nitrogen material, and masks the odor of food waste from other animals. Placing materials that are high in carbon (i.e., dried leaves) at the bottom of the pile and along the inside walls of your compost bin will provide good airflow, drainage and odor control. It is also important to harvest finished compost at the bottom of the bin every three to six months. This will discourage pests from nesting in the warm finished compost.
It is also recommended to not add meat, cheese, or leftovers containing excessive oil or seasoning. These creatures are attracted to meats, fatty foods, and cooked foods, so it is best to exclude these from your bin or pile. These animals are also looking for other food sources (i.e., bird feeders, outdoor pet food bowls, garbage cans, and fruit trees). It is a good idea to position your compost bin away from these other food sources and nesting locations!
Good compost management can deter pests while also accelerating the composting process. By being mindful of what you put in your compost bin and how you manage it, you may prevent these unwanted visitors. Every time you aerate or turn your compost pile the temperature increases, which will both speed up decomposition but also deter these animals that are looking for a dry, cool, undisturbed home and food source.