Rats Have Been Trained to Drive Cars for Science

Scientists have taught rats to drive miniature cars in the name of behavioral research.

While the undertaking sounds like an intriguing proposition in and of itself, the purpose of the study—first reported on by New Scientist—is to highlight the importance of enriched environments in lab-based animal studies.

The study's authors also hope that the results will offer additional benefits to the field of neurodevelopmental and neurodegenerative diseases, like ADHD and Alzheimer's—specifically the mechanisms and developmental trajectories of conditions in this category.

Writing in the journal Behavior Brain Research, the authors say behavioral studies like theirs allow researchers "to assess subtle alterations in motivation and behavioral response patterns that are relevant for translational research related to neurodegenerative disease and psychiatric illness."

Rat driving a car
Scientists are teaching rats to drive cars to highlight the importance of enriched environments. University of Richmond

In comparison to many of the tests that are frequently used to assess animal cognition (including object recognition tasks and mazes such as the Morris Water Maze), the challenge of maneuvering a vehicle is more complex. While tests like objection recognition tasks and mazes can be "informative," the study's authors say they are "rather simple" and cannot capture the animal's full potential behavioral range—which is where their rodent driving school came in.

For their experiment, the researchers trained animals to use a rat-operated vehicle (ROV) built from a plastic container with an aluminum floor plate. The ROV was fronted with cut-out windows and copper bars that could be used to start and steer the vehicle simply by touching or grabbing. It also meant the rat could break the ROV just by releasing the bar.

In total, 11 rats were taught to use the ROV, five of which were raised in an "enriched environment" containing multiple stories and several objects changed weekly and six in standard laboratory housing. They received bribes of the cereal Froot Loops and mini-marshmallows and as training progressed, so did the distance traveled to access the reward.

Subsequent measurements of two stress-related hormones (corticosterone and dehydroepiandrosterone) via the rats' feces suggests driving appeared to relax the animals. The ratio of dehydroepiandrosterone and corticosterone increased as training went on, signaling their stress levels were declining.

As the study authors expected, the rats that came from an enriched environment exhibited a "more robust" driving performance and, in general, appeared to show more interest in the vehicle, entering the ROV even when there was no food incentive. But the authors noted their surprise at the "lack of interest" and "under-achieved mastery" of the group from the standard laboratory housing, which was lower than they expected.

Rat in Car
The rats were bribed with Froot Loops. University of Richmond

The research backs up previous studies highlighting just how smart rats can be, even managing to outsmart humans on occasion. In this instance because they can be trained to maneuver vehicles in complex ways.

"I do believe that rats are smarter than most people perceive them to be, and that most animals are smarter in unique ways than we think," lead author Kelly Lambert, from the University of Richmond, Virginia, told New Scientist.

But the study's authors also hope that the results will help inform future research in behavioral science. The work highlights the importance of enriched surroundings when it comes to laboratory animals and suggests that "informative experiences" such as driving can boost emotional resilience and can offer psychological protection against neurodevelopmental and neurodegenerative diseases.

"It will be interesting to determine if future investigations with this task, preferably with increased numbers of animals, will reveal similar results," said the study's authors.

rat steering car
The rats were able to steer the car using copper bars. University of Richmond