re: Infestation of Rats in attic

I lived in a rental house years ago that got a rat infestation. I noticed at night they would come and go from a dogwood tree with a limb that touched the roof.

I sawed the limb down one day, and that night sat on the porch and watched them dive bomb to the ground because the couldn't get back in.

I'm not saying that's your problem, but definitely take an inventory of tree branches extending out to your house. This doesn't make a difference for flying squirrels, but can make a big difference for many other critters that can't fly.