Rat Ethology

Despite what other people may tell you, It’s important to recognize that rats exhibit a very wide range of emotions. They generally aren't given credit for this because of our perception of them as pests. They experience emotions ranging from joy, sadness, and fear, to more complex ones like the ability to empathize or regret decisions.

The ability to regret in rats was a large discovery because, before 2014, no mammal apart from humans was proven to have the capacity to experience regret. A study was done where a rat had the choice to wait in line for a favorite food or to find a less fulfilling meal elsewhere. After choosing to eat something else, some rats were observed going back to wait for the tastier food. The relevant part of this study is that the rats regretted leaving the line. Some may argue that they experienced disappointment only rather than regret, however, their orbitofrontal cortex became active, which is the same part of the brain that activates in humans when we feel regret (Johnston). The difference between disappointment and regret is a big jump in emotion. It’s the difference between being upset over missing a reward, and being upset because you recognize you could have changed the outcome.

Another emotion that has been widely studied is a rat's ability to show empathy for other rats. In one study in 2011, two rats were placed in a cage with a piece of chocolate. One rat would be restrained, while the other is free to roam and eat the chocolate. Consistently, the free rat would attempt to free the restrained rat before eating the chocolate (Bekoff). An important detail is the rat was not trained to open the restraining device, instead, it would attempt over and over until the other rat was freed. Despite it not being a simple task, the rat was determined to help the restrained rat. Many similar studies have been repeated. In one such study, a rat could choose to save another rat from drowning or eat a piece of chocolate, and the free rat almost always chose to save the drowning rat. Even in studies where one rat was not facing unbearable pain, the other rat would still choose to help.

These two emotions are the ones that are most widely studied, but there are many other studies that point out rats’ emotional intelligence. These include but are not limited to a rat's ability to experience disappointment, trade, and barter with one another, recognize they have forgotten something, and rehearse scenarios in their mind that result in a desired outcome (Sussex)

In the end, it’s important to recognize that we don't know everything about rat ethology. There is a lot of bias pulling on two ends of the rope that is our understanding of a rat's emotions. On one hand, many researchers want to use them because they are simple analogs we can use in place of humans, and would like to counter the idea that rats experience complex emotions. On the other side, there are people who hate the work done on rats in labs and are willing to spread the most minor or poorly proven piece of evidence of rats' ability to express emotion. So many things said about rat ethology should be taken with a grain of salt.

Despite all of this, it is a safe thing to say that rats display a more complex set of behaviors and emotions than the public and some researchers often give them credit.