Posted: 29/10/2013 at 18:04
They can get through tiny gaps, they can virtually flatten themselves. Also they can gnaw through wire netting and breeze blocks - I grew up on a farm and I've seen it.
If they want to get into your compost heap they will - the best thing to do is to keep it damp and to turn it frequently so they can't set up home there for too long. Keep disturbing them.
If you have rats aroun under no account put potatoes or peelings in your compost - spuds are their favourite food and a member of my family who is a large commercial potato grower has amazing stories of the lengths rats will go to in order to get at potatoes.
I have wooden compost bins and I don't keep all the rain out - I lay sheets of heavy duty cardboard and carpet over the top to keep most of it out, but I don't let it get too dry and cozy.