The Mexican jumping bean can remain active for several months depending on what time of year it is and how the bean is cared for. The movement is actually caused by a moth larva that has attached itself to the inside of the bean.
When heat from a person's hand is placed against the bean, the larva moves to get away from the source of heat that is creating a dehydration risk. Since the larva is destined to turn into a moth, the jumping action of the bean could never exceed the annual life cycle of the insect. Soaking the bean in non-chlorinated water every couple of months and keeping it in a cool, damp place can keep the larva from perishing.