Each Electronic Butterfly in a Jar is a jar with a wire in it. The wire has a fake butterfly on the end. Somehow, when you tap the top or make a loud sound, the electronics in the cap make the wire wiggle. This creates the very realistic illusion of the butterfly flittering around your jar. It even just stays on the glass and flexes its wings sometimes. There is absolutely no way you can look at a Electronic Butterfly in a Jar and not smile.