Opossums have long whiskers that, at first glance, seem to be placed at random with no obvious pattern. While smell is widely understood as their most important sense, those whiskers may play an equally important role, or possibly an even greater one.

Their whiskers are extremely sensitive to movement. Have you ever seen an opossum move its head from side to side, pointing it toward an object, rubbing against something, or remaining completely motionless? All of these motions are an effort to gather information. This behavior is called whisking. Each whisker is wired independently to the brain. Movements of the head are not necessarily meant to see, hear, or smell better; rather, the opossum is likely whisking to collect information that isn’t available through other senses.

Opossums use specialized muscles to move each whisker independently, greatly increasing sensory input. This information gives them a detailed picture of their surroundings, in some ways similar to how bats or dolphins use sonar.

When a whisker comes into contact with an object, it produces vibrations, and even sound. Using muscles at the base of each whisker, an opossum can move its whiskers rapidly, effectively scanning its environment for instant feedback. They can vibrate their whiskers up to 25 times per second, making this one of the fastest movements a mammal can perform.

Air currents also provide valuable sensory input. Even slight disruptions in airflow may warn an opossum of other animals nearby, potentially conveying information about shape, size, distance, direction, and speed.

In complete darkness, whisking may help with navigation and identifying materials in the environment, such as where fresh air is coming from, whether something has been disturbed recently, or the density of an object. Whisking likely provides an enormous amount of information that we cannot fully comprehend.

Opossums have existed for at least 100 million years, and likely much longer,* while humans have been here for less than one percent of that time. We cannot hope to fully understand everything they perceive or know.

Although there has been limited research in this area, what has been studied suggests whisking is of major importance, essentially an additional sense beyond those familiar to us. Whisking sends messages directly to the areas of the brain that control some involuntary functions and memory. Data gathered from whisked objects is stored for future use, supplementing natural instincts.

This allows opossums to rely on millions of years of genetic memory while also adding new information, which may be passed on to offspring. Decisions about when and what to eat or drink, where to sleep, and even where to relieve themselves are influenced by this genetic memory, with whisking playing an important role in shaping it. These are the survival skills that have allowed opossums to persist for so long.

In my own experience with opossums, I’ve learned they can sense many things in conditions where the usual senses are nearly useless. This helps explain the almost magical sixth sense I’ve observed in them. After all, magic is merely science we don’t understand yet…

See: “How Did I Became Me” on this website.

Sources:

TheConversation.com, theconversation.com/topics/whiskers-19234; Maayan Shain, neurosciencenews.com; Weizmann Institute of Science; Prescott, T.J., Mitchinson, B., Grant, R.A. (2011), Vibrissal Behaviour and Function; Sofroniew, N.J., Svoboda, K., National Library of Medicine; Grant, R.A. et al., The Evolution of Active Vibrissal Sensing in Mammals; Manchester Metropolitan University, Small Mammals Scan Surroundings by Vibrating Whiskers.