Here's some info on mice that you might enjoy,I found it this morning.
Computer mice, historically, attached their "tails" to the backside of a desktop personal computer and hung out in their "pad" beside the keyboard. PC users often went to great lengths to find or make the most decorative and colorful "pad" for their mouse, where he (or she!) could rest in ease! Technicians even designed a "ball" the mice could roll on so the mice didn't have to tire their legs moving about in their pads.
But!-- Alas-- Computer users grew to dislike the rubber decorative pads, and soon even began to dislike their mice! Users wished to have their mice be contained under the pad, rather than supply a separate "pad" which the mice could enjoy. Today, most mice live inside--rather than beside--their desktop or laptop "home". You can always know there's a computer mouse in your computer by watching him (or her) run around when you just touch the pad-- the mouse makes a little line dance on the monitor as you "tickle" the mouse through the pad. And today, instead of using his/her little ball to move around, computer mice use them to push the computer fan around and around! And if you listen very closely, you will sometimes hear computer mice squeaking; the squeaks are mixed in with the fan sounds!