Mice May Be Able to Recognize Their Own Reflections


The study conducted at the University of Texas, published in the journal Neuron, suggests that mice demonstrate the ability to recognize themselves in a mirror, albeit with certain limitations. Led by neuroscientist Takashi Kitamura from the Southwestern Medical Center, the research team applied a white mark to the foreheads of mice with black fur.

According to the study, mice marked in this manner spent more time grooming their heads in front of the mirror, indicating an apparent attempt to remove the ink stain. However, successful removal occurred only under specific conditions: the mice needed prior familiarity with the mirror, interaction with mice resembling them, and a relatively large mark.

The mirror or mark test, developed in the early 1970s, has been applied to various animals to determine if they can recognize themselves in a mirror. If the animal explores or attempts to remove the marked spot on its body in front of the mirror, it is considered evidence of self-recognition.

Children typically pass this test at the age of 24 months, but in the animal kingdom, only a few species have demonstrated success. Elephants, various primate species (such as rhesus monkeys, chimpanzees, and macaques), dolphins, and even magpies have exhibited such self-awareness. Recently, this capability was also observed in pigs and roosters.

However, adjustments were made to the experimental setup for pigs and roosters, as it was believed that these animals might feel uncomfortable in the “artificial” experimental environment, potentially compromising the test results. Pigs, for instance, showed indifference to color markings, requiring a food incentive and several hours of mirror exposure. Roosters, on the other hand, had a simulated bird-of-prey attack, and their behavior when facing the mirror was observed.

Is This Consciousness? Or Just Recognition of Change?

The researchers made some adjustments to the testing environment for the mice as well. To prevent the mice from reacting to the tactile stimulus of the mark on their forehead, the researchers initially used black ink for the black-haired mice and then switched to white ink. With black ink or very small marks (0.2 centimeters in length), the mice showed no reaction, indicating that it was not a response to the tactile stimulus. However, with larger white marks (0.6 to two centimeters), they spent significantly more time in front of the mirror grooming their heads.

Does this test now demonstrate that mice also have consciousness? The scientists are cautious about making such a claim, as it requires further investigation. However, it is established that mice can recognize a change in their own appearance and respond to it.