Can Rats Laugh?

Some people like them, some people hate them, but rats have been right alongside us as a species for a very long time now. Some researchers have even discovered that we have been keeping rats as pets as far back as the 16th century (via National Library of Medicine). So it's no surprise that human beings have always had an endless fascination with how rats behave. As far as lab testing goes, we have been using rats in medicine and scientific research for 150 years (via Scientific American), which makes them one of the most valuable animals on the planet. Despite this storied history, however, there's obviously still one burning question we are all dying to know: can rats laugh?

The answer is a resounding yes! Not only can rats laugh when tickled, but they also enjoy it. That's good news for rat lovers everywhere. This type of phenomenon isn't exactly exclusive to just one animal either, as researchers have discovered a whole host of animals who also laugh (via NPR). We just have to do away with our own human definitions of what laughter is. 

Everyone has laughed at least once in their life (and hopefully much more) but why do we do it? The answer to that may lie in our genes, and how our social bonds developed through evolution. Some researchers think that laughter evolved in primates as a way of bolstering social bonds, which makes a lot of sense when you consider that people often laugh together as a way of sharing in a positive moment (via Mental Floss). Another theory is that laughter mostly developed as a self-defense mechanism to keep our bodies safe. Ticklish areas of our body are vital locations, and it could be one way of our body warning us about danger.

As noted by Mental Floss, psychologists have discovered that there are actually two different types of tickling sensations we can experience: knismesis and gargalesis. Knismesis is when you feel light sensations on your skin, oftentimes followed by itching, and gargalesis is the type that actually makes you laugh out loud, which is experienced by many animals, like rats. 

A researcher by the name of Jaak Panksepp had been working on the answer to this question for years now and had discovered that rats produce their own form of laugh when appropriately tickled (reports Scientific American). Rats, like humans, also engage in social behavior and enjoy playing with each other and being played with. Panksepp's work has revealed that rat laughter has varying tones and pulsating sound bursts that can be recognized as laughter and that they emit these noises when engaging in play. 

As explained by Scientific American, rats love being tickled, either by each other or by humans, and that laughter is one way that rats can further develop bonds with each other. But this is not exactly like how humans laugh, as human beings have a sense of humor and can tell each other jokes, while rats cannot. Laughter here is closer to sounds of pleasure, a signal that they are enjoying the sensation being felt.

It goes to show you that a lot of animals aren't so different from us after all, and we can find a bit of our own behavior in much of the animal kingdom.