It's not an April fools prank, just an everyday prank, but here's one from years ago that I thought was funny.

I shared office space with a co-worker for 10 years at a hospital, and we were very close. We played practical jokes on each other and occasionally shot each other with paper clips and rubber bands. At one time we had a problem with mice in our office, and she was very scared of them.

I created a mouse using the cotton from an aspirin bottle, colored it gray and attached a rubber band for the tail. While she was out to lunch, I placed the "mouse" under the cartridge of her typewriter.

My friend came back from lunch and started making phone calls. While she was on the phone she started to type, but something was wrong. She opened up her typewriter and lifted the cartridge.

My friend SCREAMED into the phone, then jumped completely over her desk. After she regained her composure from screaming, and I regained my composure from laughing, she said...."Let's go do this to Pam!"