Given a choice between eating chocolate alone and rescuing their pals, rats will apparently save their pals and then share the chocolate with them. Trapping a rat in a cage sparks its cagemate into action, as it figures out how to open the cage and liberate its jailed friend. This is an unusual example of rats expressing empathy, a trait thought to be reserved to us higher mammals, the primates.
It’s interesting from an evolutionary perspective, because it suggests that pro-social behaviors originated earlier than previously thought. And it’s interesting from a neuroscience perspective, because it suggests rats are wired for pro-social behaviors, which means they can be used as a model for human behaviors.
So that’s interesting.