Yes, they are real! Yes, they jump! And yes, we have them!
Mexican jumping beans come from mountains of Mexico. In the spring, moths lay their eggs on the flowers in the trees. The egg burrows its way into the seed. The egg turns into a larva which eats the soft insides of the bean, which in turn makes the skin of the bean hard. Their jumping is created by the larva trying to escape the heat.
Each little box comes with five little beans (real larva inside).