A complex Web.

• Position: ECOLOGY - Brief article

[ILLUSTRATION OMITTED]

A few years ago, when scientists tried to protect Kenya's acacia trees from leaf-munching animals like elephants and giraffes, they noticed something strange: Instead of thriving, the trees withered and died. The investigation that followed uncovered a complex relationship among the animals, the trees, and a species of ant. The ants nest in the trees' thorns and sip their nectar, ready to attack when the tree is disturbed by a...