Intelligent Rodents

One of my favorite speakers in the pest control industry is Dr. Bobby Corrigan, a rodent enthusiast, or, as he’s more professionally known, an Urban Rodentologist. Some of the most useful information I have learned about rodents has come from seminars Dr. Corrigan has led. In one such event that I watched recently, he talked about rodents and how fascinatingly intelligent they are. In our industry, we often think of rodents as a nuisance, mere vermin that we as pest control professionals are to eliminate. While that is true, have you ever stopped to consider the rodent itself? Perhaps learning more about them can not only expand our knowledge of what we do and why we do it but also help us more efficiently control these pests.

Small but Smart-Rats

Rats came to the Americas at least as early as the eighteenth century amid colonization and the expansion of global trade. Rats love ships. Once rats found their way onto them and arrived at new ports, they were in heaven: they had ships, food commodities, and water. The ports became places where rodents learned to thrive. This goes to show just how adaptable and creative they are. They learned to expand their palate by eating what they could find, and they ultimately learned how to survive in new environments. (They probably did so better than you and I would!) Because of their ability to adapt and learn they have had a thriving, constant presence here in the United States. To this day rats have a broad palate and will eat what they need to survive. They have a very similar palate to my own: they see something, and they eat it! If you are up to date on your rodents in the news, you may be familiar with one little rat caught on video dragging an entire slice of pizza along with him at a subway station.

Another example of the cleverness of rats was on full display across the world in 2020. As the year was marked by quarantines and fewer restaurants and other businesses being open, the hustle and bustle of a pre-pandemic day on many city streets started to become replaced by rodents. They were charging the streets in large numbers in search of (what else?) food. Corrigan essentially explains this phenomenon by asking, “when do we normally see rodents?” We expect to see them during the evening hours when the danger of humans is minimal and, by that time of day, there is a buffet of leftovers in trash cans, alleyways, and more. Typically rats would expect to leave their cozy nests at night and then find dinner with ease. Imagine then if one day your dinner is not there, then after a couple of days of not eating, you and I would be not in good shape. We would be stressed and panicky. Rats are just like us; they are intelligent mammals that require a meal. They conclude that if the food can no longer be found during the evening, they will have to change their strategy and brazenly begin looking during the day. Rats again have shown their capacity for adaptation in response to changes in their environment.

These are just a few examples of how clever these rodents are and how this has led them to be a successful species. Corrigan claims that the rodent population is so successful that in order to make an impact on the species you would have to eliminate 96% of their entire population. Although this may sound like bad news to some, for those of us in the pest industry, it means a whole lot of job security and also having our work cut out for us.

Rodents are more intelligent than we give them credit for. They, like humans, have been found to use tools to help them eat or use them as security to protect their burrows. They are also excellent communicators. If you have ever met me in person, you may find that communication is my strong suit; it has been said that I could make conversation with a fly on a wall. However, for some of us, this is not the case. Rodents are even better communicators than I: they are constantly communicating with other individuals of their species. When pest control professionals are trying to locate a rodent problem, we are looking for what we call “signs of rodents,” such as rodent dropping or urine stains. For us, they are signs of rodent communication. Rodents communicate chemically with each other, have loud calls and mating dances, and have means of alerting others from their species of danger, food, water, or shelter. In a recent article published in 2019 scientists were able to teach rodents how to drive tiny cars. Using tiny cars constructed of plastic with an aluminum base, rodents “drove” with three copper wires acting as a steering wheel; depending on which wire the rat would touch, it would move the car in that direction. They would drive these cars to collect their food! Can you imagine if rodents started using vehicles to get their dinner every night? We would have to start reinventing how we eliminated these pesky mammals.

This is all just scratching the surface in showing how truly intelligent these little critters are. They are a thriving species and quite possibly one of the smartest ones on earth. Knowing this should give us great pride when we are able to help successfully eliminate colonies of rats. They are smart and know a trap when they see it, so pat yourself on the back the next time you help a customer. In the words of Bobby Corrigan, “rats are much more than meets the eye, ear and even nose!”

Kristen Stevens, BCE