Making compost is a great way to make your own organic soil amendment for free. Many people make compost and never have a rat problem. Others give up composting because they find that their compost bins or compost heap attract rats.
This might seem odd. But, in reality, rats are attracted to some compost bins and not others. You need to recognize why a compost bin may be attracting rats. Then you can solve the problem as quickly as possible. They aren’t attracted to the compost as such. Rather, they are attracted to food in the compost and the shelter that it might provide.
Why do compost bins attract rats?
Rats are scavengers, always on the lookout for food. So if you add things like meat, fish, poultry bones, dairy products, fat, or even vegetable scraps to your compost, it’s likely to attract rats, mice, squirrels, and any other rodents that might live in your part of the world.
Rats are also always searching for shelter, particularly a warm place to make a nest. A nice, dry compost pile will almost certainly meet these rodent needs.
Be ultra-aware that mice, rats, and other rodents carry diseases. They are also a huge nuisance and may invade your home once they have found shelter in your compost bin.
You need to get rid of them sooner rather than later.
How to get rid of rats in compost bins
You have to be proactive to get rats out of your compost bins. If whatever they’ve been attracted to isn’t eliminated, they aren’t going to leave of their own accord.
However, if you take steps to remove any food sources and get rid of what attracts them to the nest, they probably won’t stick around. But you need to take action as soon as you become aware of any level of rat infestation.
Rats are horribly common in North American residential areas. And if you don’t get rid of them, the reality is that they are going to multiply.
According to the Alabama Cooperative Extension System, one pair of rats can produce between 6-12 babies in 21 days.
It takes only 3 months for a rat to reach sexual maturity. So, provided they get enough food, water, and shelter – which a compost pile could provide – they could feasibly multiply into more than 640 rats in 1 year!
House mice, they say, could multiply into several thousand in a year!
How to prevent rats from coming back into compost bins
As stated above, to stop rats from coming back to your compost bins you need to change whatever is attracting them in the first place. The answer lies in eliminating food and shelter opportunities.
An open compost heap or compost pile is going to be more difficult to pest-proof than a compost bin. But if you don’t add food items and ensure that you keep your compost consistently moist, you’ll have a very good chance of preventing rats from coming back.
Nadine VanZandt of the University of Vermont’s Extension has some invaluable tips. She points out that perfect compost needs a balance of nitrogen-rich green materials, carbon-rich brown materials, as well as water and oxygen.
Green materials include green grass clippings, green plant trimmings, vegetable and fruit scraps, biodegradable tea bags, rinsed and crushed eggshells, and coffee grounds. Brown materials include dry grass clippings, sawdust, wood chips, straw, cardboard, brown paper bags, egg cartons, toilet paper rolls, and coffee filters.
These all need to be cut up small to encourage quick decomposition. The smaller the bits are, the faster they will turn into compost.
Don’t add food to compost that might attract rats
Don’t add any food waste from cats or dogs whether it is raw or cooked. Also avoid dairy products, unrinsed eggshells, and any sort of oil.
Apart from generating horrible odors, these foodstuffs potentially contain dangerous bacteria.
When you add food scraps to your compost, it is essential to cover it totally with a layer of brown materials.
Alternatively, put all food waste into a Bokashi bucket – a Japanese term for fermented organic matter. You can even break down the meat and dairy using this fermentation process.
Keep your compost damp
If your compost is damp it’s not going to make a nice, warm, cozy nest that will attract rats. But you don’t want it to be wet because it won’t get enough airflow to decompose properly.
Instead, too much moisture will end up in a slimy mess that is likely to attract flies and other pests. Just keep it moist and turn the compost in your bin or pile it regularly to aerate it.
VanZandt recommends turning the compost every other week. Each time you do this, add a new layer of brown material on top.
Use a compost bin that prevents rodent access
This can be difficult because many rodents will chew their way through anything – wire, wood, plastic, or even commercial compost bins. But if you start with a hard-sided compost bin with a lid, and use physical barriers to prevent access to the bin, you may have a solution.
The master gardeners of Contra Costa County have some good ideas. These include a removable top and wire mesh under the bin to stop burrowing from underneath.
Two other ways that people use to get rid of rats are traps and poison. We don’t believe that either of these is a good idea.
Using poison to get rid of rats
For starters, there are numerous commercial rodenticides available and they do work in indoor settings. But poison is one of the cruelest, most toxic methods to get rid of any living creature.
In outdoor environments, including areas that contain compost heaps and compost bins, pets and other animals are likely to find the poison and eat it. Then the vicious circle begins.
Any animals, including rats, mice, rabbits, and squirrels that eat poison are likely to die. Then there is a very real risk that dogs, cats, foxes, hawks, and other birds and animals will eat the dead carcasses. Inevitably, they too will be poisoned and die.
Using traps to get rid of rats
Many people use both traps to catch rats and mice, some of which kill the rodents. This approach might have some success, but there is a caveat or two.
Unless you can ensure that only rats and mice have access to your traps, there’s a chance that they will catch other creatures. Of course, it depends on what wildlife gains access to your property, but typical examples are chipmunks and squirrels.
Ultimately, unless you change the environment that is attracting rats to your compost, the rats will keep coming back. It’s not going to matter how many you are able to trap and/or kill.
Compost does attract rats, but usually only if it contains rotting food and/or provides shelter for rats to breed. The best solution is to ensure that your compost doesn’t meet the needs of rats in the first place.