A Mexican jumping bean is an occurrence native to Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

, where it is known as Frijoles saltarines . Physically, Mexican jumping beans resemble small beans, tan to brown in colour. They are a seed pod through which the larva of a small moth has chewed. The bean "jumps" because when it gets in a hot place the larva snaps its body hoping to roll to a cooler place. The beans are from a shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

  often referred to as the jumping bean

After the egg hatches, the larva eats away the inside of the bean, making a hollow place for itself.