There's nothing to give you a quick case of the creepy crawlies quite like seeing a rat scuttle by in front of your feet. Then there's the loss of appetite brought on watching a long-tailed rodent scarf down his breakfast of subway trash while you wait for your train. And, of course, we can't forget what happens when a big fat rat suddenly climbs out of your toilet.
Sure, rats are gross, they look gross and they do gross things. Then again, so do many of us humans. As a team of scientists recently discovered, rats are a lot like us in one unexpected way. They smile, shriek, laugh and squirm when tickled, as detailed in a new study in the journal Science.
Researchers spent three years on the unenviable task of getting close enough to laboratory rats to reach out and tickle the daylights out of them. The scientists found that the rodents responded in much that same way that many humans do when stroked with human fingers on the belly and other sensitive spots. The rats "produced noises and other joyful responses," according to the research team. In other words, they wriggled, giggled and sometimes even chased the tickler's had around the cage for more.
The experiment wasn't just about trying to get a smirk out of a species that's usually the one making us squirm. It also might shed some light on the human brain activity that creates emotions associated with tickling. The researchers found that joy and laughter can come from stimulating the somatosensory cortex, which is the receptive area that responds to touch.