The first thing you need to know about rats is that they like warm, quiet, safe spaces to live. Compost heaps and bins can reach 40° C, a vital part of the composting process, making them a cozy spot for things like rats and even the odd hedgehog.
Preventing rats in compost starts right at the beginning of your composting journey with the location of your bin or heap, the type of container you select and how you use it. Here are our 5 steps to prevent rats and other vermin:
1.Locate your bin in a high traffic area - Putting your bin or heap close to a garden path, near the washing line or close to where the kids play means there will be regular noise and movement around the bin making it less appealing to rats. Also avoid putting bins or heaps close to typical rats runs which tend to be along fence lines, sides of buildings and the edges of raised beds.
2. Consider investing in a rat proof bin - Rat proof bins are available to buy, these often have a solid base and well-fitting clip on lid or are tumbler style bins that sit above the ground.
3. Rat-proof an existing bin - For the most part rats get into bins when lids are left off, open or just don't fit properly or by burrowing underneath. There are a few ways to rat proof an existing bin. First, ensure the lid fits well and snugly to the bin. Second, place the bin on a concrete slab, paving stones or a decent layer of pebbles to ensure they can't burrow underneath though this also limits mini-beasts and worms too. If a solid base isn't for you, line the base of the bin with several layers of metal mesh (galvanised welded wire is probably best), off-set your layers to ensure that the holes are as small as possible and definitely no bigger than 1.5 cm across.
4. No cooked food, oils or fats - Avoid putting food, especially foods rats might like, in your compost bin or heap. Compost heaps are best kept to garden waste alone. If you have a compost bin this is a great way to get rid of peelings etc but avoid adding meats, fish, bread, cooked food, oils and fats. Eggshells are great for your bin but rats can be attracted to any egg that remains inside so if you are particularly worried about rats it is best to leave these out too.
5. Regularly disturb the bin - The more often you use your compost bin or heap the less likely you are to get rats in it. Adding a few leaves every day, rattling the lid as you pass the bin and regularly mixing your compost all help deter rats. A compost bin or heap with regular human visitors doesn't seem nearly as safe to rats as one that is left undisturbed for days or weeks on end.