Rodents, rats cited, can chew through cinder blocks and joints between them.
They think they want to get in they find the weak spots a little opening or whatever or just someplace to sink their teeth and they will get in.
Depends on how bad they want in I guess. If you find holes where they got in the expanding foam will plug it and they don't like to chew on it, so I hear. Won't stop them from finding other places maybe.
Same for buildings if something doesn't drive them away.
The Speedwell Academy circa 1800 the squirrels were climbing the brick walls and chewing the shutters up to get in and eaves.
They sell solar powered leds that flash red that are somewhat effective on Racoons, oposuums etc and sonar repllers that you plug into outlets. I've got those in the basement but I regualarly spray perimeter in and out with home defense. They don't like that and other products either.
A resident cat or rat terrior maybe will stop them. Rat bait will get them.