Homer wrote:
Sounds like a chipmunk, the little buggers love to chew plastic. I have had to replace most of my downspout extensions at the stix n Bricks, because of them. I have actually stood and watched them chew the plastic. The foam is about the only real good way to seal them out. I don't know if they will chew foam or not, never have known of a case where they have.
You may have explained some of the damage to my white plastic lattice panels. They also love peanut butter. I use it in mouse traps but they have gotten hit at times.