Well, I woke up to the sound of regular sized squirrels thumping around on the bedroom roof, and the cat frantically pacing them along the length of the wall, but I think it was normal squirrel activity, and that a regular squirrel would be too big to get in through that hole, until we can have it patched.... (to be fair, the cat probably wouldn't get that much exercise without the ceiling squirrels to track).