With April fools not to far off I could use a few suggestions for work. Besides the rubber band around the sink squirter here's a few I have been accused of.

Tie a thread to a plastic spider and the inside of the kitchen cabinet pull. Put the spider in the cabinet and it jumps out when someone opens the cabinet (Women just love this one).

Long heavy zip tie around their drive shaft.

Salt and sugar look very similar.

Carpet fresh on the top of ceiling fan blades.

Suggestions held strictly confidential.

All good ones. I do have a annoyatron. We set it up in the IT guys office on occasion.