DAVID GREENE, HOST:
As far as we know, rats do not play music. Something they might regret, seriously. There's new research in the journal Nature Neuroscience suggesting that rats, like humans, experience regret. A team of scientists from the University of Minnesota set up some restaurants, little restaurants for rats. When inside, rats can wait for better food options or move on to another spot for quicker, less fulfilling fare. It was supposed to be the equivalent of walking into your favorite, only to find it was ridiculously long wait. So you go to the fast food joint next door. When the rats did, yes, they showed signs of regret. Scientists said, sometimes the rats would pause and look back at the better food they had missed out on. It is believed to be the first time regret has been identified in the species other than we humans. No word, yet, on whether rats feel regret for the nuisance they cause, rooting around in the dumpsters outside your favorite restaurant. Transcript provided by NPR, Copyright NPR.