Rats will chew through wood too.I have some extra 1/2 hardware cloth which I will use to make the the house is secured up. It might sound weird but seeing those things in with my chickens fired me up and I need to kill some rats!
Making an "apron" around the entire coop and run will help o keep them out.
This thread will give you a few good ideas:
https://www.backyardchickens.com/th...ound-coop-and-hardware-cloth-question.352928/