Some of you may worry about your kids leaving the nest at such a young age. But don't loose any sleep over it. Natal dispersal is a perfectly natural thing. It's what happens when young animals leave home to make a life for themselves. Birds leave the nest and mammals leave their home territories.

Scientists think there are a number of reasons why young animals leave home. By doing so, they avoid competing with their relatives for resources. They avoid competing with each other for mates. And they also avoid inbreeding which can lead to less healthy offspring.

Not all animals disperse, but let's take bears as an example. Scientists have been keeping track of bear dispersal in many parts of the world. Most bears leave their mother's territory before they reach sexual maturity at age five.

In Scandinavia, ninety-four percent of brown bear males and forty-one percent of females leave their natal territory. In Canada, grizzly bear males and females leave their mother's territory, but males leave in greater numbers and travel farther than females. In Virginia, black bear mothers encourage their young to move away at one year of age and males even swim across rivers to find a new home.