When humans want to take a baby out, they simply pick them up. But how do cats carry their little kittens when they need to “relocate”? Do they carry them on their backs? Hold them in their arms? Or pick them up with their mouths? Actually, small animals have a special “carrying” area—right at the back of their neck! When a cat’s neck is grabbed, it’s like being gently “pinched” by a binder; it’s as if they’re frozen in place. However, the moment you let go, the cat immediately “unfreezes.” So, what’s going on here?
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Stay Still, Stay Still, Mommy Is Moving Me
This phenomenon is called “clipnosis,” a combination of “clip” (as in “clamp”) and “hypnosis.” Why the neck? One theory suggests that the area at the back of a cat’s neck is “dead tissue,” meaning it doesn’t hurt when it’s grabbed or pinched, which is why adult cats carry kittens by this spot. However, the idea of “dead tissue” not hurting doesn’t explain why cats freeze when their necks are clamped. Another hypothesis is that the back of the cat’s neck is a “nerve channel” and that pinching it blocks this pathway, causing the cat to freeze, much like being “hypnotized.” Yet, these theories don’t quite hit the mark. This interesting and widely known “myth” didn’t escape the attention of scientists. Professor Tony Buffington, a clinical veterinary medicine expert at Ohio State University, conducted a study on this behavior. In addition to his curiosity, Buffington was also interested in exploring the feasibility of using this method to stabilize cats for medical examinations. The experiment involved 31 cats aged 1 to 5, of various sexes. The “clamp” used in the experiment was a simple 2-inch binder clip, shown in the image. After their necks were clamped, the cats would stop moving, arch their backs, and tuck their tails between their legs. Tests on the cats’ physiological indicators revealed that this behavior wasn’t caused by fear or pain. The cats’ pupils didn’t dilate, their heart rates didn’t increase, and their breathing remained normal—all physiological reactions typically observed in animals that are startled were absent in the clamped cats. Buffington’s team concluded that this behavior is related to the “ease with which mother cats move their kittens.” While this simple explanation may not fully satisfy science enthusiasts, Buffington used a more fitting term in his article to describe the behavior: “Pinch-induced behavioral inhibition.” This term purely describes the phenomenon without suggesting any underlying cause. The researchers believe the behavior is related to the “mother cat transporting her kittens.” In fact, in many species, juvenile animals display a “frozen” state when picked up by their mothers, including mice, rats, rabbits, dogs, and guinea pigs.
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A Similar Phenomenon in Human Infants
Finally, in 2013, a group of Japanese neurobiologists studying the physiological responses of animals being picked up by their mothers discovered that a similar “calming effect” exists not only in mice but also in human infants. The three most typical physiological responses, which are strikingly similar between human babies and mice, are: stopping crying, becoming more compliant, and a decrease in heart rate. The significance of this research is that the “consistency of physiological responses across species” allows scientists to study the underlying causes of these reactions using mice (instead of human infants). The findings not only explain the “clamp-freezing” phenomenon in cats but also answer another question more relevant to humans: why does picking up a crying baby and gently rocking them calm them down? In the experiment, the researchers anesthetized the sensory nerves at the back of the infant mice’s necks (the somatosensory neurons). This weakened the calming effect caused by being picked up. At the same time, surgery that removed a part of the brain to interfere with the incoming signals to the cerebellar cortex prolonged the time it took to calm the baby mice. These experiments show that if the mice cannot sense that they are being grabbed by the back of their necks, they will not curl up. If the cerebellum doesn’t receive the signal, the mice will not show compliance. The decrease in heart rate and the change in body posture are directly controlled by the parasympathetic nervous system and the cerebellar efferent nerves. This series of physiological responses helps the baby mice stay calm, compliant, and curled up, making it easier for the mother to carry them to a safe place.
So, a clip can freeze a cat, but it’s not because the flesh at the back of the cat’s neck is “dead.” Instead, it’s the sensory nerves in that area that send the signal to the kitten: “I’ve been picked up.” The subsequent physiological responses, which are similar to being “frozen” or “paralyzed,” aren’t caused by “nerve channels being blocked.” Rather, they are the result of signals from the brain (including both the central and peripheral nervous systems) guiding the cat into a state that makes it easier for its mother to move or transport it.
