Rats are known to display empathy and altruism. For example, they will attempt to free a trapped comrade and exhibit pain and anxiety responses at the sight of another rat in distress.

A new study by researchers from Portugal bring even more evidence of altruism in these animals. Experimenters placed rats into pairs and provided one of the rats a choice: open one door and get a food morsel for yourself; open another and both rats receive a reward. Out of 15 rats tested, all but one made unselfish choices consistently. The rats in fact selected the prosocial outcome around 70 percent of the time.

Disclaimer: Stop UBC Animal Research does not condone or endorse any animal experimentation.