Researchers find that when one rat encounters another trapped in a restrainer, the free animal usually helps the trapped one by figuring out, as these two are doing, how to open the door to the trap. That helpful action happens faster and more consistently when there are multiple free rats.

Researchers find that when one rat encounters another trapped in a restrainer, the free animal usually helps the trapped one by figuring out, as these two are doing, how to open the door to the trap. That helpful action happens faster and more consistently when there are multiple free rats.