This Week in California Wild is a joint project of California Wild, the science and natural history magazine published by the California Academy of Sciences, and the Biodiversity Resource Center, a branch of the Academy's Library. Each week library and magazine staffs cull a wide variety of news sources to compile the most important and interesting natural science stories. With Fierce Rattle Battles Lions roar.
Elephant seals bash each other bloody.
But when the unassuming caterpillar faces off against an uninvited interloper, it drums the leaves of war. The discovery upends the concept of caterpillars as leaf-munching milquetoasts. After hatching, each caterpillar spins a little silk tent on a leaf to keep out both predators and the elements while it eats its way around the neighborhood. Constructing these pavilions takes so much energy, suggests Yack in the Proceedings of the National Academy of Sciences, that they're worth defending against trespassers. If the intruder fails to cease and desist, the resident starts drumming its mouthparts as well, setting up a threatening vibration that usually sends all but the biggest outsiders packing.