Can trees talk? Yes—but not in words. Scientists have reasons to believe that trees do communicate with each other. Not long ago, researchers learned some surprising things. First a willow tree(柳树) attacked in the woods by caterpillars(毛毛虫) changed the chemistry of its leaves and made them taste so terrible that the caterpillars got tired of the leaves and stopped eating them. The even more astonishing, the tree sent out a special vapor — a signal causing its neighbors to change the chemistry of their own leaves and make them less tasty. Communication, of course, doesn’t need to be always in words. We can talk to each other by smiling, raising our shoulders and moving our hands. We know that birds and animals use a whole vocabulary of songs, sounds, and movements. Bees dance their signals, flying in certain patterns that tell other bees where to find nectar(花蜜) for honey. So why shouldn’t trees have ways of sending messages? 小题1:Why did Caterpillars stop eating the leaves of a willow tree? (No more than 15 words) 小题2:According to the passage, how do bees communicate with each other? (No more than 5 words) 小题3:What is the main idea of this passage? (No more than 5 words)