Read this then scroll down for the movie.

Alex lent me his Mexican Jumping Beans for a week so I decided to make a little film of them 'jumping' before they hatch into moths.

According to Alex, the beans are called 'Brincadores' in Mexico and the moth larvae are called Carpocapsa saltitans. What happens is the moths lay their lavae in the fruit of a shrub called Sebastiana palmeri or Sebastiana pavoniana where it eats the inside of the fruit and makes a home for itself. Eventually, the larvae makes these little threads which (when you warm them up) they can use to make the bean jump.

To be honest, jump is quite often an exageration but as you can see from the movie below, they are far from immobile... I will leave it to you judgement as to what you call them.