^^^ That is what I was thinking as well.
To some degree...
Not really, but it's a 170 year old limestone that used to be a carriage house for much of it's life. I'm sure there are garter-snake sized cracks between the stones in a few places. They very rarely come inside though.
I did manage to see where last week's squirrel was getting in. I waited him out and next time he was at the birdfeeder I fixed that bit of soffit/fascia. He was mad.
Later that evening I was hooking up the speakers I had moved in the garage. As soon as I connected the left and it came on, loudly, that same squirrel was apparently sitting on it and it freaked him out, he jumped and squawked, so did I, and then he ran off and hid in the ceiling. I left the music blaring and the door open all night.