This is a fun and easy prank for April Fool’s Day! I did it last year and my coworkers loved it. Get the download here.
All you do it cut out a square (there are probably more than enough there for you!) and then put a piece of tape over it (be sure the writing faces the sticky side). Now use it to cover the laser on your coworkers’ mouses (mice?) and wait for their reactions! The paper will prevent the mouse from working. But your victim needs only to turn their mouse over (probably suspecting the batteries are dead) to see they’ve been tricked!