Squirrels are smart critters. We had one in the attic once and my bro in law went up there and plugged up the hole so he couldn't get back in.
But that damn squirrel came down to the yard while we were having a B-B-Q and stood on it's hind legs and raised a racket, all the while looking at my bro in law.
So my bro in law who says he knows "squirrel talk", went back up on the roof and removed the wood that he had placed there only a few hours earlier.
As soon as he removed that blockage, a terrified female squirrel came running out and made a dash for the nearest tree and joined up with that male squirrel.
They were seen yesterday living happily ever after on the lower levels of the backyard redwood tree and the male still comes down and raises hell whenever the bird feeder is empty.
True story.