Scientists have decided something strange, after trying to tickle some animals - especially rats.
When the scientists started to tickle rats, they used a machine that detects high pitched frequencies and makes them audible to our weak human ears.
These recordings showed that the rats were making noises while being tickled. This noise was laughter!
Everyone loves being tickled! Scientists found that after tickling rats, the rats would begin to enjoy the person's company more.
They would start to play with the trainer's hands, and constantly follow the hand wherever put theirs!