when I lived in NZ we bought a dishwasher and it was fine until one night the thing started beeping all the time in the middle of the night. I unplugged it and called the shop where I bought it the next day. The service engineer came round and pulled the machine out to give it the once over. I was outside doing something but he came out saying "I think I've found your problem" holding a very large rat in his pliers by the tail.
The rat had come through the plasterboard wall from under the house and chewed through a cable under the dishwasher. In the process frying the microprocessor and also the rat. It wasnt covered in the warranty needless to say!
Found a baby mouse once in a FCU mounted 6ft up a wall - it had crawled out of attic down wall and in through cable entry of steel back box. Was very surprised to see it there.
I used to work on chicken farms , and when you went into a barn and turned on the light the floor came alive with rats , urgghh ! They got on all the control gear and boards ...
I work a lot in NG sites and we are told we are never more than 10M away from a rat. Weils disease is a real risk of coming into contact with rat urine so be careful!