Behavior: Animals That Kill Their Young

For India's langur monkeys, infanticide works

In his classic work On Aggression, Nobel Laureate Konrad Lorenz argued that man is the only species that regularly kills its own kind. This concept, which contrasted the order and restraint in the animal world with the chaotic aggressiveness of man. reflected the mood of the time: the shadow-of-the-Bomb pessimism of the '50s and early '60s. But Lorenz was wrong; since 1963, when his book was published, naturalists have identified dozens of species that kill their own, including lions, hippos, bears, wolves, hyenas, herring gulls and more than...