英语时差：墨西哥跳豆为什么会跳跃？（下）

Once the seed is gone, this larva has a peculiar fondness for leaping about inside the empty pod, making its new home jump and roll from place to place. These larva even rig up a network of silk lining inside the pod, to help transfer more jumping energy into the seed pod wall and make it hop and roll farther. But, why do these larvae want to jump in the first place? Jumping beans tend to jump more when they are warmed up. In fact, the heat of your palm is enough to start that larva wiggling. It’s quite possible that they jump in order to get their seed pod out of the hot desert sun–and into a shadow perhaps. After all, these larvae stay inside the seed pods for months, waiting to change into adult moths. They may jump to avoid being roasted!