Don't mind the scarecrow is always losing the head when he fails to scare them the ordinary he always resorts to this old trick.

I guess the mice had been eating their way through his thoughts...they would peep out of his eyes but comes a time they had eaten his head enough for it to fall off...it didn't half frighten my little girl...after that I could never convince her that it wasn't alive...it became a Stephen King trope for her and she never trusted it again.