hello, i've recently (past two weeks or so) noticed a squirrel (looks to be an adult, here he is saying hi this afternoon https://imgur.com/a/CT5w06j) hanging out on my double-hung windowsill. sidenote: i got one of those U-shaped air conditioners this past summer, and since most of the window can stay closed, i decided to leave it installed during the winter this year. normally that space would be closed completely during the winter months.
he (or she?) is relaxing in the space between the main window and the storm. i don't mind at all, but he seems to be chewing at the insulation foam a/c side curtain things. (they look like this https://imgur.com/a/wyshRwx) i'm worried he might chew all the way through and come into the house (not ideal, esp since i have an almost 18 year old dog who would probably be pretty confused/upset), so I'm thinking of replacing the foam with some wood panels.
but other than the concern about him coming inside, i love the little guy and would like to help him feel comfortable out there! i'm just wondering whether it's detrimental for him if i leave him snacks and stuff since I'm unable to bring him indoors. should i just leave him be? sorry i tried searching around for advice but found lots of conflicting information about ruining his ability to survive in the wild, some posts about how I'd be inviting massive destruction onto my house by not immediately shooing him away, etc, etc. thanks for any guidance!