I know the plastic PVC pipes, but the rats can eat it. I use metal pipes:
(this is not my house i get this picture in the Internet).
I do not like hidden wiring when it is hidden something quite unknown in what condition it is. So I have the wiring in boxes outside, and passes through the wooden walls are made with metal pipes. Rats come every autumn, I destroy them, but a year later they are back again.
This was due to the fact that some people make a garbage dump in the forest. The truth is now all removed and nothing is lying, but the dump can ever occur again. We have a lot of uneducated and stupid people who used to throw garbage anywhere. And then we get a crowd of rats. And in the cities of all the horror, they have built a special sorting plants, but they are still stupid throw all the garbage in the same tank. I'm not concerned about environmental issues, just irritates me that they sprayed the resources, it's absolutely unprofitable. Once I stayed on the job in the city of late, I missed the train and went for a walk near the vegetable market near the railway station. So the rat went there straight on the road, I counted several pieces.
Trust me, you don't want him sitting on you. Because there's no sharing a chair with that dog. 
