Few animals other than monkeys have hand-like paws. The monkey, like man, has an opposable thumb-that is, it can place its thumb opposite its other fingers. By pressing its first finger against its thumb, a monkey can pick up things as tiny as a flea(跳蚤). Because other animals lack this thumb, it is difficult for them to pick up small things and carry them.
The monkey's ability to grasp rice with its paw often leads to its capture. Hunters lay a coconut(椰子) with a handful of rice, leaving a hole in the shell of the nut. The monkey has no trouble sliding its paw through the hole. But it can't draw the paw out while it is holding a fistful of rice.
Since it is often too stupid or greedy(貪婪) to open its hand, the monkey is unable to free itself from this simple trap(陷阱).