Rats are considered highly social animals that become attached to each other, love their families and can bond with their human owners.
It is believed they are capable of empathy and can recognise and react to pain in others.
A study by Jaak Panksepp, a neuroscientist at Bowling Green State University, found when rats are tickled they make chirping sounds that are similar to human laughter.
‘[Y]oung rats have a marvellous sense of fun’, said Dr Panksepp, adding that the rodents bonded with the human tickler and liked to be ticked as much as possible.
Contrary to their reputation they are also very clean animals and groom themselves regularly.
Rats are highly social animals that become attached to each other, love their families and can bond with their human owners
In September last year researchers from New York University found when rats are frightened in the day, the fear centres in their brains are re-activated during sleep – potentially helping to strengthen memories.
Researchers say that rats store maps of what they experience in both of their hippocampi – two curved structures inside the brain.
Different places that the rat experiences are processed by different groups of neurons that activate together in sequence as a rat runs around a maze.
After exploring an area, these sequences have been observed replaying as the rat sleeps – comparable to dreaming of the paths they’d taken when they were awake.
Researchers believe that this allows memories to be stored in the long term.
The most recent research by the University of St Andrew’s found rats help each other out in return for favours in a similar way to humans.
The rodents were found to groom food-providers more often than partners who had refused to help.
In addition, common Norway rats offered more food to those who cleaned them, researchers found.