Yes but you need to put down a predator apron around the perimeter of the run and coop. And rats are smart. Look any place a rat can get inside.
No. I could not find it at a store. I had to order it and waited 3 weeks for delivery.
Don’t know the chemical makeup!
The wire is a welded wire mesh coated with a black PVC coating. The PVC coating probably gives off some gases while curing, when the fence is first produced. I didn't notice any particular odor. I was using it outside and did all my cutting to size outside on sawhorses.