Like humans rats have regrets too, a new study has found.

The feeling of regret was previously believed to be primarily human. However, the new research shows that even rats possess this particular cognitive behavior.

Researchers conducted a 'Restaurant Row' test in which the rats had to decide how long to wait for food. "It's like waiting in line at the restaurant," Professor David Redish, of Minnesota University said in apress release. "If the line is too long at the Chinese restaurant, then you give up and go to the Indian restaurant across the street."

The research team noted that the rats decided to move from one 'restaurant' to other depending on the food offered. The rats then found that the next one offered was a less tasty.

Due to this, rats stopped and looked back at the previous food offered and were more likely to wait for longer for some flavourful food.

Professor Redish said they had to be cautious to design the study in order to monitor signs of regret and not just disappointment. "Regret is the recognition that you made a mistake, that if you had done something else, you would have been better off," he said.

"The hard part was that we had to separate disappointment, which is just when things aren't as good as you hoped. The key was letting the rats choose."

He explained that in humans, a part of the brain called the orbitofrontal cortex is active during regret. "We found that in rats recognising that they made a mistake, their orbitofrontal cortex represented the missed opportunity," Professor Redish said.

He said that the rat's orbitofrontal cortex represented what the rat should have done, not the missed reward. "This makes sense because you don't regret the thing you didn't get; you regret the thing you didn't do."

The study was published in the journal 'Nature Neuroscience'.