英语时差：聪明的章鱼

Chimps do it. Dolphins do it. Even crows that want to catch fish do it. But an octopus? Yes, it seems the smartest member of the invertebrate world has learned how to use a tool. Octopuses have a reputation for being clever. They can figure out how to pull a plug out of a glass jar to get to food. They have been known to escape from holding tanks. They have the ability to navigate mazes and seem to be able to remember past experience. But tool use? That does seem incredible. Tools, by definition, are objects that have no purpose until they are used for a specific function. Scientists have known for some time that octopuses make use of shells and other objects they find to hide from predators. But observations of veined octopuses, known as Amphioctopus marginatus, off the coast of Indonesia surprised scientists. Not only do they use coconut shells to hide beneath, they carry the shells with them.