Looking like a drowned rat? Never fear, a dry rat may come to your rescue. 
 
 An experiment testing whether empathy can drive behaviour in rats has found that, when a dry rat observes a distressed rat trapped in a wet chamber, it will free it from its cage. 
 
 Not only are these rats willing to help others, they do so faster if they themselves have previously suffered a soaking. 
 
 "This suggests that knowing that soaking is distressing enhances the rats' motivation to help their cage mate," says Nobuya Sato of Kwansei Gakuin University in Japan. "We think this comes from empathy." 
 
 We knew that some non-humans feel empathy, but proving that it can motivate friendly and helpful behaviours towards others in non-primates has long been a challenge. 
 
 Set me free 
 
 Then, in 2011, Peggy Mason of the University of Chicago and her colleagues showed that rats would free their cage mates if they were trapped in a distressing restrainer apparatus. 
 
 That experiment provided compelling evidence that rats could empathise with another's discomfort, but questions remained over whether they were really acting solely to help their cage mate out. Perhaps they were just freeing them so that they could have someone to play with. 
 
 To test this, Sato put some rats in an unpleasantly wet chamber, and others in a dry one. He was surprised to see that rats showed no interest in freeing individuals that were housed in a dry chamber – they only helped rats that were soaked and distressed. 
 
 "When the rat is in the space without the pool, they don't open it for him. They don't see a problem," says Mason, who likens this to how a human might behave. "We're probably not that different. If somebody looks like they're happy and they're just hanging out, why would you help them?" 
 
 Evolutionary behaviour 
 
 Sato's team also showed that rats learned to open the door to free a wet rat more quickly if they themselves had previously been soaked. 
 
 This could suggest that a bad experience made their empathetic actions more urgent. "It shows that memory can facilitate emotional empathy," says Mason. 
 
 Empathetic helping behaviour in mammals is thought to have evolved from maternal behaviour. It makes evolutionary sense for a mother to be able to guess the emotional states of her offspring, and to act accordingly – feeding, cleaning, warming or comforting them as appropriate. 
 
 This work, together with Mason's 2011 study, shows that the benefits of helpful empathy extend beyond the juvenile stage, says Mason. "They generalise to mammals more broadly – both genders, throughout their lifespan." 
 
 But there may be another explanation for the speedier rescue actions. It is possible, says Sato, that these rats opened the chamber quicker because they had already observed how the door mechanism works when they were soaked. His team plans to test if this was the case in their next experiments. 
 
 Journal reference: Animal Cognition, DOI: 10.1007/s10071-015-0872-2 
 
 If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to. ||||| Rats have more heart than you might think. When one is drowning, another will put out a helping paw to rescue its mate. This is especially true for rats that previously had a watery near-death experience, says Nobuya Sato and colleagues of the Kwansei Gakuin University in Japan. Their findings are published in Springer's journal Animal Cognition. 
 
 Recent research has shown that a rat will help members of its own species to escape from a tubelike cage. The helping rat will show such prosocial behavior even if it does not gain any advantage from it. To see whether these rodents will also help when one of their own is about to drown, Sato's team conducted three sets of experiments involving a pool of water. One rat was made to swim for its life in the pool, with another being in a cage adjacent to it. The soaked rat could only gain access to a dry and safe area in the cage if its cagemate opened a door for it. 
 
 Sato's team found that rats quickly learned that to help their distressed and soaked fellow rat, they had to open the door. The rats were, however, only quick to open the door when there was actually a truly distressed cagemate nearby who needed to be saved. The experiments also showed that rats dislike being soaked. Those who had a previous experience of being immersed in water were also much quicker at learning how to save a cagemate than those who had not been immersed. 
 
 The researchers also watched what happened when rats had to choose between opening the door to help their distressed cagemate or accessing a different door to obtain a chocolate treat for themselves. In most cases, rats chose to help their cagemate before going for the food. According to Sato, this suggests that, for a rat, the relative value of helping others is greater than the benefit of a food reward. 
 
 The results indicate that rats show empathy. These rodents can share in the emotional state of members of their own species, in this case that of distressed animals. 
 
 "Our findings suggest that rats can behave prosocially and that helper rats may be motivated by empathy-like feelings towards their distressed cagemate," says Sato, who believes that studies of sociality, such as empathy in rodents, are important for understanding the underlying neural basis of prosocial behavior as well as evolutionary aspects.
– Rats may not have the best reputation, but a new study suggests that they're actually pretty good citizens. Researchers found that if a rat is in distress in water, another will save it, according to a post in Science Daily. Researchers put one rat in a pool of water and another in a dry area, with the two separated by a door. The dry rats soon learned that they could let the other rat through the door, thereby rescuing it—and they hurried to open the door only if the other animal seemed to be in real distress. What's more, rats who knew what it was like to be soaked, having been through it themselves, learned about the rescue mechanism faster than others. "This suggests that knowing that soaking is distressing enhances the rats' motivation to help their cage mate," a researcher tells New Scientist. "We think this comes from empathy." In fact, those in the experiment seemed to care enough about their struggling brethren to forgo chocolate for them. Given the option of saving a fellow rat or getting a snack, they tended to opt for the rescue first. Previous studies have also pointed to empathy in rats, but further work is needed to be sure, researchers say. (Elephants, meanwhile, have been seen to console each other.)