If you were outside in the cold, you’d want to find a nice warm place to shelter in. Mice are no different. Compost heaps can offer warmth, protection and quite possibly some food too.
Unfortunately, humans are not always so keen on mice in the compost heap. But is it a problem? And if it is, what can you do about it? Let’s find out…
Finding mice in your compost bin can be an unpleasant surprise. These pesky rodents love burrowing into warm, food-filled compost piles to nest and breed Left unchecked, mice can hamper your composting success and potentially spread disease.
Getting rid of mice in compost takes diligence, but it’s possible with the right techniques. This guide covers everything you need to know to deter mice humanely and protect your black gold compost.
Why Mice Love Compost Bins
Mice seek out compost bins for three main reasons
Warmth – Compost heaps provide an inviting refuge from cold weather. As organic materials decompose, the compost warms up like a cozy nest.
Food – Compost bins contain a bounty of kitchen and garden scraps for mice to munch on. Meat, grains, fruits and vegetables are like an all-you-can-eat buffet.
Shelter – The enclosed environment of compost bins allows mice to hide safely out of sight. They can burrow passageways and build nests to breed undisturbed.
Understanding what attracts mice helps guide prevention methods. Let’s look at signs of an infestation.
Detecting Mice in Compost Bins
Spotting a mouse invasion early allows quicker action to remove them. Watch for these common indicators:
- Droppings around or inside the compost bin
- Chewed up food scraps or shredded newspaper/cardboard
- Tiny footprints in the soil near the bin
- Burrows and nests among compost materials
- Strange smells coming from the compost
- High-pitched squeaks, especially at night
- Visual sightings of mice, particularly in evening/morning
Impacts of Mice Infestations
While a couple transient mice likely pose little harm, a large infestation can create several issues:
- Disrupted decomposition from burrowing and nesting
- Unpleasant odors from excess droppings and urine
- Increased risk of disease transmission from feces
- Loss of compost materials as mice consume scraps
- Attraction of other pests like rats to the bin
Getting the mice under control quickly restores a healthier compost environment.
Deterring Mice Humanely
Now let’s explore humane tactics to evict mice from compost bins or prevent their entry in the first place:
Mouse-Proof Bins – Use enclosed compost bins with tight-fitting lids, small vents, and mesh screens across openings. Elevate bins off the ground.
Limit Food Scraps – Avoid adding meat, fish, oils or cheese that strongly entice mice. Stick to plant-based foods only.
Turn Compost – Stir and turn compost weekly to disrupt nesting sites and bury food scraps.
Natural Predator Scents – Place used cat litter or dog hair around bin perimeter to deter mice.
Smelly Herbs – Spread garlic, pepper, peppermint or mustard powder around the bin. Mice dislike these strong scents.
Physical Barriers – Use hardware cloth or wire mesh under bins to block entry from below. Create gravel moats around base.
Remove Shelter – Get rid of hiding spots like ivy, woodpiles, etc near the bin for nesting.
Natural Repellents – Apply predator urine granules around the bin exterior. Check product safety.
Persistence with these deterrents should convince mice to leave and search for easier food sources elsewhere.
Excluding Mice from Outdoor Compost Piles
Open outdoor compost heaps require extra fortification. Try these tips:
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Choose sunny, exposed pile locations away from buildings and walls.
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Build piles on wire mesh or paved bases. Use pallet bins with tougher barriers.
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Install plastic sheeting or metal bands around the lower 12-18 inches of piles to thwart digging.
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Cover piles with weighted tarps or blankets at night when mice are active.
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Move piles away from exterior fences or walls. Mice dislike open areas.
With improved containment and natural deterrents, you can successfully exclude mice from outdoor compost.
Removing Stubborn Mice
Sometimes mice stubbornly remain despite best prevention efforts. The next step is physically removing them through:
Live Traps – Capture mice unharmed and release 5+ miles away to prevent return.
Snap Traps – Quickly dispatch mice but use caution around pets. Place under boards.
Bucket Drowning Setups – Rodents cannot escape buckets with water. Inhumane drowning method not recommended.
Glue Boards – Also inhumane. Avoid these sticky traps that cause prolonged suffering.
Poisons – Avoid poisons which also threaten other animals through secondary poisoning.
After removing all mice, seal up entry points and continuously monitor bins with deterrents to prevent re-infestations.
Preventing Mice Returns
Mice are excellent climbers and can squeeze through tiny gaps. Stay vigilant after removing them:
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Seal all possible entry holes and vents with wire mesh or hardware cloth.
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Frequently empty and turn compost to disrupt potential nest sites.
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Maintain perimeter defenses like predator scents, smelly herbs, and physical barriers.
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Clear away exterior hiding spots near compost bins.
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Monitor areas closely until certain all mice are completely excluded.
With dedication to exclusion and deterrence, your compost can stay mouse-free long-term.
When to Seek Professional Help
For severe mouse infestations, it may be wise to contact professional pest control rather than tackle the issue yourself. Seek help if you notice:
- Large numbers of mice after implementing deterrents
- Mice appearing shortly after previous removal efforts
- Signs of nesting or breeding within compost bins
- Risk of structural damage from excessive gnawing and burrowing
Pest control pros have advanced techniques, bait stations and stronger chemical poisons to fully eradicate stubborn mice.
Coexisting with Mice
While mice can be a nuisance, remember they play important roles in nature as prey for larger wildlife. Unless they pose health risks, their presence can be tolerated through smart precautions:
- Use enclosed compost bins and turn piles frequently to limit nesting
- Avoid adding meats, dairy and oils that strongly attract mice
- Wear gloves and wash hands after composting
- Keep compost away from dwelling exterior walls
- Use traps humanely and release mice far away
With proper sanitation and deterrence, composting can continue while minimizing negative impacts of mice. Implement exclusionary methods, maintain cleanliness, and monitor your bins routinely. With time, you can achieve a harmonious coexistence with mice in your garden ecosystem.
Good luck keeping those pesky mice out of your compost! Let us know your best tips in the comments.
Hose them out
I haven’t tried this method before, but Garden Organic suggests soaking your compost heap with water.
“To get rid of them, soak the heap several times over a period of a few days. An easy way to do this is to flood it using a hosepipe. Once the material is totally wet, the mice should move to drier accommodation.” (Source: Garden Organic: Mice in the compost heap.)
One problem I could see with this is your compost heap would get too wet, forcing oxygen out of the heap or bin. This would disturb the composting process and potentially delay the time until you get finished compost.
The perfect consistency of your compost should be that of a sponge – after you have wrung the sponge out. Of course, if it’s in the middle of summer and you’re in a heatwave, things might be different.
The idea of planting mint to deter mice is attractive. Do the job once and you have an ongoing mouse-prevention system in place.
However, I’ve always been skeptical about whether mint would actually work. Perhaps I’m biased – other companion planting experiments I’ve tried haven’t always worked.
But in the course of researching this article, I discovered the experiment below. This did use concentrated peppermint oil, with a stronger smell than a plant, but the results are encouraging. Perhaps mint would work!
(Do remember that mint spreads like wildfire, though, and is best constrained to large pots.)
How to stop mice in the compost heap…
You’ll often see recommendations to proof your compost bin with wire.
This might work for rats but mice are extremely good at getting into small spaces. With their super flexible skeletons, a mouse can squeeze through a 6mm gap – that’s about the size of a pencil. You can, however, get a special mouse-proof mesh.
If you don’t want to go down the mesh road, an alternative would be to source an enclosed compost bin made out of gnaw-proof materials, such as a compost tumbler.
The Secret to Rat-Free Compost Bins (It’s Easier Than You Think!)
FAQ
Are mice in compost a problem?
Composting is a great way to manage your waste. Not only will you be sustainably recycling the food scraps and yard trimmings you generate all year long, but you will also have nutrient-rich soil for your garden. If not done properly, however, composting can result in major rodent issues in and around your home.
Can you use compost that has had rats in it?
Compost that has come from a bin or heap that rats have lived in can be used in the garden but avoid using it on fruits or vegetables that are going to be eaten raw and the edible parts may be in contact with the soil or compost e.g. radish, celery, cucumber and strawberry.
Can you put dead mice in compost?
How to make a rodent proof compost bin?
Consider adding walls around your compost pile using scrap wood or metal mesh. Even chicken wire will help prevent invasion by larger animals. If you have a lid that’s a bit loose, consider putting a heavy object like a couple of bricks on top to keep the lid secure.