Dueling mice

A few months ago, our computer mouse was acting up. (What is it about electronics that don't last??!?) After a few test drives, A picked out a pretty expensive new model, but what the heck, ergonomics are important, right? The problem is, our hands are different sizes so the new mouse hurt my hand. A managed to fix the old mouse; thank goodness we can use both wireless mice at the same time. Now you can tell who's been at the computer last, based on which mouse is sitting next to the keyboard.