In this article, in an experiment led by Bartal and Peggy Mason, professor of neurobiology at the University of Chicago, it was discovered that rats exhibit empathy-like helping behavior. They found that rats consistently freed companions that were trapped inside clear restrainers, and that this behavior was driven by a rat version of empathy. The most interesting part of the experiment was when they tested albino rats in helping behavior with black-hooded fur patterned rats. Free rats, which were always albino, were first tested with trapped albino strangers they had never previously interacted with, even by smell. Free rats quickly became consistent openers for these albino strangers. However, when free albino rats were tested with a black-hooded stranger, however, the majority did not open the restrainer for the trapped individual. By contrast, albino rats who were housed with a black-hooded companion were observed to consistently liberate their black-hooded cage-mates.