What are your best memories of harmless pranks pulled off by kids

[KitFox]

42. At slumber parties

we always pulled telephone pranks. Our favorite was someone in an an overly nasal voice would say, “Is Hubert there?” Then wait a minute or two and call same number and ask for Hubert. Call one more time and then on the next call someone in a deep voice would call and say, “Hello, this is Hubert. Have there been any calls for me?”
A good prank I pulled on my students (3rd grade) while learning measurement. I had them go about the room measuring and recording things they chose. Then we would gather on the carpet and I would bring out my very realistic looking can of Peanut Brittle which was actually one of those jokes that had 3 big coiled cloth covered spring snakes in it. I would ask someone to measure the can and then ask if what I had in the can would have to be the same measurement or could it be longer. Some kids thought no. Some said yes and concluded things like string. Then I would say let’s open it and find out. Boing! The snakes sprung out of the can and the kids rolled with laughter!