It makes me wonder if I can make my cat laugh?

http://www.glumbert.com/media/ratlaugh

Perhaps so!
http://mfrost.typepad.com/photos/uncategorized/2007/04/09/put_some_pants_on.jpg

How do they know the rats aren't really saying, "stop ****ing with me with your big dirty hand"?

Those rats looked like they couldn't get enough of Mr. Hand. :)

Ya know... if my world wsa as small as that cage i'd probably go chasing a foreign object if it wsa thrown in my face and forced on my body long enough too!