From Science:
Whereas most animals run away from the dangers of the African savannas, meerkats, brave little souls that they are, race toward them. Large groups run headlong at venomous snakes and other potential predators, harassing them with jeering noises and pokes from their tiny claws. Scientists have long thought the meerkats were somehow protecting their colony, but new research suggests that the odd behavior may also be a way for younger meerkats to learn more about their enemies. If so, then it may lead biologists to take a second look at other social species, such as prairie dogs and vervet monkeys, which behave similarly.
Biologists Beke Graw and Marta Manser of the University of Zurich in Switzerland studied meerkats in the wild. When they released cobras and other predators near the colony, the meerkats mobbed the snakes and became aggressive. They also mobbed innocuous critters, such as moles and squirrels–even empty cages–but eventually lost interest and drifted away. Meerkats responded differently according to their age. Adults between 1 and 2 years of age mobbed intruders longer and growled, barked, and poked more intensely than did younger and older animals, the team reports in this month’s issue of Animal Behaviour.
More here.