How to Keep Rats Away From the Compost Bin?

How to Keep Rats Away From the Compost Bin?

Many gardeners prefer not to make compost in their own homes. They don’t mind spending a lot of money to buy the compost they need from vendors, and who can blame them? Having your home turned into a breeding ground for fat, creepy rats is more than unsettling. Learning how to keep rats away from the compost bin is an essential gardening skill. Rats thrive in the warmer months, so they tend to multiply at alarming rates during the summer. These rodents do not have any problems with moving from your compost bin into the comfort of your home. Rat feces and urine carry numerous deadly microbes and pathogens that could cause a disease outbreak to crops and humans if they get mixed in with the manure or dragged into the house by pets and shoes.

Using rat poisons and traps may seem efficient, but they could cause harm to humans and domestic animals in your home. Poisons could also get mixed up with the compost and affect the yield of plants, so it’s best to go the natural way when eradicating pests in the garden.

One of the main attractions for rats is a dry space. If your compost is always dry, you’re basically making the perfect rat nest. Keeping your compost moist at all times, excluding cooked food waste from the heap, and adding small amounts of mint are some of the most efficient methods used to keep rats away from the compost bin.


5 signs rats are in your compost bin

Droppings in and around the compost bin

If rats are in your compost bin, they’d definitely leave some droppings occasionally for you to find. Depending on when you check the bin, the droppings could be slimy fresh or dried up. Either way, rat droppings are quite easy to identify. They have a dark brown color and a rounded oval shape, similar to a grain of rice about 10-14mm in diameter. Rats could egest about 15-20 droppings in one night, which could lead to a larger number over time. If you notice rat feces inside your compost bin when you have to add new items, or around the corners of the bin, you definitely have a rat problem on your hands.

Rat nests

Rats are natural spawners, producing a lot of offspring in one breeding period. They’d require a dry, hidden, and undisturbed location to nurse their newborns. If you notice sparsely-made nests of lint, fabric and dry leaves, rats are most likely nesting in your compost bin. If your compost materials are dry and high in carbon content, you might find some naked rat babies in the bin.

Ammonic stench

Like the urine of most other animals, rat urine is high in ammonia and it leaves a rather musky odor in your garden. Their urine is also high in calcium which causes it to form white residue when it dries. If you don’t immediately notice the other signs of a rat in your compost bin, rely on your nose. You’d definitely be hit by the strong smell if you get within a few inches of the bin. Rats carry diseases that can be transmitted through their urine, another reason to keep them away from your compost bin.

Scratches on the compost bin

Rats have extremely sharp teeth with very rough enamels and sharp claws. They can scratch, bite and burrow through almost anything. They may not get through thick plastic and metal, but they’ll try. If you notice scratches and bite marks around your compost bin and at the top, you have some ‘esteemed guests’ looking to get in. If you’re using a cardboard box more or a light plastic bag as your compost container, rats would most likely get in at the first trial. You’d find tears and holes all around it.

Burrows around the compost bin

If rats can’t get into your compost, they would usually try to get in from under the ground. Also, they need a place to spawn their offspring and store the food they extract from the bin. The brown rat is the highest burrowing culprit of all the rat species, and they are also very common. If you notice tunnels and holes around your compost bin, you probably have rats pilfering your materials. This is usually the case when you have food waste in the heap.

8 ways to keep rats out of your compost bin (rat-proofing techniques)

Use a thick, solid-sided compost bin

Rats have hinged ribs at their spinal cords that allow them to collapse their bodies and squeeze effortlessly through tight spaces. If you have open-sided compost bins with holes, it’s best not to use them for brown compost materials only, such as dried leaves and grass. Green materials such as moldy cheese, fruits, and vegetable waste should be decomposed in a solid compost bin or tumbler with a lid. Using a plastic bag, a lidless bucket or a cardboard box will probably cause a rat infestation in your compost, garden, and home. Make sure the lid covers the bin perfectly. Rats are intelligent animals who look for signs of weakness in forts designed to keep them out. They’ll scratch, claw, and bite their way into almost anything, so extra caution must be taken with the bin or container.

Keep eggshells and cooked food out of the compost mix

Avoid adding strongly aromatic foods into your compost heap because rats have a powerful sense of smell. Cooked foods and raw meat decay faster than dry materials. This would cause the release of numerous odoriferous gases that would attract the rodents. Eggshells in the compost attract rats even though they decompose very slowly. They contain calcium and sulfur and may begin to smell terribly from the remnants of slimy egg white in the inner shells. Although eggshells keep snails and slugs away from the compost because of their sharp edges, they’ll attract rats very quickly.

Keep the contents of your compost bin moist

Rats are hairy animals and as such, they thrive in dry places. If your compost is too dry, it would be easier for rats to spawn and breathe in the confines of the bin. When it’s wet, unpleasant gases are emitted faster and the condition became unbearable for the rats. Moisten your bin regularly depending on the climate in your location. It may have to be moistened more frequently in the summer than any other season.

Do coffee grounds repel rats from the compost bin?

Yes, rats have a strong dislike for the smell and taste of coffee grounds. This is one of the most efficient methods of keeping rats away from the compost. Coffee particles will also help the compost decompose faster. Rats do not eat them and if they happen to tongue a bit of ground coffee, your compost becomes a rat-hazardous zone. Sprinkle generous amounts of finely ground coffee beans around your compost and inside it. You may have to do this regularly due to wind and rain dispersion of the particles.

Keep the compost bin away from edges and quiet places

Rats cower at the slightest sounds and they do not like being disturbed. They also don’t like being seen, so they tend to run along walls, edges, corners, and fences. Keep your compost bin in a location where there’s a fair amount of foot traffic. If it’s too close to a corner or a fence or isolated at a faraway position, rats would be fully obliged to make homes in it. Rats also take to trees, bushes, and shrubs where they can get some measure of cover, so it’s best to keep your bin away from these areas.

Add a few leaves of mint into your compost

Rats are repelled by the cool, peppery flavor of spearmint. Gently tear up a few leaves to release the flavor and drop them in and around your compost bin. This method alone might not exactly keep away the larger, hungrier rats, but it could work well with another method to keep them out completely.

 Bury your food waste deeply under the heap

Food waste includes raw food items, potato peels, fruits, and vegetables. Bury these organic materials deeply under the brown compost materials such as grasses and the Bokashi. Rats would have a hard time digging through the protective layer to get to the real deal.

What if rats are already in your compost bin?

If you haven’t applied any of the steps above and your compost bin is crawling with rats, you might want to get rid of them before starting again. If one rat comes by the compost bin once in a while, chances are, it wouldn’t drop any significantly harmful waste. However, if lots of rats are making comfy homes in and around your compost, the best option is to get an exterminator to remove the entire heap from your garden.

It’s not ideal to extract lots of rats and continue composting. This is an unhealthy practice. Rat feces and urine are highly dangerous to plant and human health. It’s recommended that you give up the overrun heap and start over. Clean out the bin and the entire area before applying some of the methods above when you start your new heap.

Should the compost bin be covered?

Under normal circumstances, a compost bin doesn’t necessarily have to be covered. Air is abundant in oxygen and nitrogen, two elements that are essential to the decomposition process. However, with the rat situation factored in, it’s best to place a tight lid over your compost bin. A closed bin can also accelerate the rate of decomposition through the anaerobic reaction where moisture and heat are retained for a faster breakdown. Covering it also prevents rain from over-wetting the heap and the sun from over-drying it. The bin would stink very terribly when opened, but it’s a small price to pay.

Keeping your garden clean and rubbish free to prevent rats

Rats like dirty, cluttered environments to keep them warm, hidden, and covered. If your garden is bushy, dirty, scattered or littered, you might be creating the perfect rat haven. Keeping your garden clean is an integral part of the gardening process. It doesn’t only make it more attractive, but it keeps it rodent-free. Here are a few helpful tips to help you give your garden a tidier look:

  • Keep your gardening equipment and tools in a shed. This includes buckets, gallons, and hoses.
  • Remove unnecessary shrubs and overgrown grasses.
  • Sweep fallen leaves regularly and add them to your compost heap.
  • Remove broken pieces of wood, plastics, and fabric.
  • If you have an event in the garden, clear out refuse and food pieces immediately.

Rats can make gardening a lot tougher than it should be, but if you can keep out before they come in, you’ll definitely have a happy time gardening.


  1. Diseases directly transmitted by rodents. CDC. Retrieved 07-10-19
  2. Colleen Vanderlinden. The Basics of Bokashi Composting. The Spruce. Retrieved 07-10-19