The Rat Pack

Oh, those Norway rats. You see them hanging out in cliques, doing what all the cool rodents do, following the "in-crowd."

A bunch of conformists, that's what this blog always said. We heard all the usual arguments: "But only humans and chimps exhibit those kinds of copy-cat behaviors." To which we replied: "Oh, really? Is that a fact? Try telling that to a guppy - once you can drag one, kicking and screaming, off whatever bandwagon passed by this time."

At long last, we no longer have to resort to haughtiness and indignation whenever this topic is raised --and it is raised, really, we swear, sometimes even by someone else. The June issue of Animal Behavior reports that Norway rats, just like chimpanzees and humans, show "a tendency to copy the behavior of others (that) can completely override the tendency to engage in behaviors personal experience indicates are superior to those in which others are engaged."

In other words, Norway rats like to follow the mischief (or "herd" or "pack" if you want to use a less hopelessly obscure term for a group of rats, which, frankly, we don't).

In the study, conducted by Bennett G. Galef and Elain E. Whiskin of McMaster University in Ontario, rats were trained to recognize that one food was toxic and another safe to eat, or that one kind of food was tasty and another less palatable. After interacting with "demonstrator" rats that had already eaten the food, the rats ignored their previous experiences and chose to devour the bad-tasting or toxic food. What's more, they would keep eating the bad food as if they had no better alternatives - just because they'd seen their friends do it.

Although conformity was long thought to be an exclusive human trait, researchers are beginning to realize that other animals - including chimps, guppies, and now Norway rats - exhibit the same behavior. As Galef and Whiskin write: "Furthermore, in both rats and humans, the greater the discrepancy between the information provided by models and the subject's own personal knowledge, the less likely the subject is to behave in accord with the socially acquired information."

Just like back in high school.

Today in Mice