Lollllllllllllllllllllllllll!! That is just too darn funny.
My one cat did the same thing. I set my spool down on the table, next thing you know the cat snuck up and whacked the spool... took ahold of the tiny thread and ran through the whole house with it. He thought it was a game that mommy was chasing him. It was not funny. lolllll, okay, well it was. But I was not laughing at the time. lollll.