Whiskers

Whiskers, also called vibrissae, are special hairs that help mammals feel their way. These tiny hairs act like very sensitive feelers. They help animals notice air movements and objects around them. This helps mammals move, find food, and know where they are without using their eyes.

Whiskers grow in groups on different parts of an animal’s body, like above the eyes, on the chin, and near the ears. Almost all mammals have whiskers, especially those that are active at night. However, a special group of mammals called monotremes do not have whiskers.

Even though only mammals grow true whiskers, many other animals, such as birds, fish, insects, and crustaceans, have similar structures that help them sense their surroundings.

Etymology

The word "vibrissae" comes from a Latin word meaning "to vibrate." It describes how these special hairs move. In humans, we have thick hairs inside our nostrils.

thick hairs

Evolution

All mammals today had a special kind of hair called whiskers in their ancestors. Scientists think this may have started even before true mammals, in ancient animals from a time called the Triassic period. Today, most mammals still have whiskers, except for great apes. They also have special face muscles that help move them.

Anatomy

Whiskers are special hairs that help mammals feel their way around. Unlike regular fur, whiskers are stiffer, thicker, and longer. They grow from special parts of the skin that have many nerves, helping the animal sense things nearby.

Many mammals have whiskers in groups on their faces. Land animals like rats and hamsters often have four main groups: above the eyes, on the cheeks, where a mustache would be, and under the snout. These whiskers help the animals move, find food, and know where their paws are. Marine animals like whales and dolphins have different whisker arrangements, sometimes around their blowholes instead of their snouts. Whiskers can be very long and help these animals sense their environment in ways that eyes cannot.

Main article: follicles

Main articles: somatosensory cortex, Marine mammals, whales and dolphins, Florida manatee, electroreception, keratin, nerves, blood, sinus, guinea pig, afferent nerve cells, mechanoreceptors, sensory nerve, Euler spiral, chinchilla

Operation

The follicles of whiskers on some animals can move. Tiny muscles at the base of each whisker let mammals change the position of their whiskers.

Whiskers help animals feel their way, especially when they can’t see well, like at night or in muddy water. They can also sense wind and show an animal’s feelings. Whiskers are important for many animals, including rats, in finding food and behaving with each other.

Marine animals like seals use their whiskers to feel vibrations in the water, helping them find food even in the dark. These whiskers are very sensitive and can detect fish swimming by. Some seals can follow trails left by fish minutes earlier. Unlike land animals, seals keep their whiskers still to get the best sense of their surroundings. Research continues to learn more about how these whiskers work.

Lines of research

Neuroscience

Many mammals use whiskers to feel their way around. The signals from whiskers travel through the trigeminal nerve to the brain. They first go to a part of the brain called the trigeminal sensory complex in the brainstem. Then the signals move to places like the thalamus and the barrel cortex. Scientists study this because it is simpler to understand than vision. Lab rats and mice rely more on whiskers than sight.

Evolutionary biology

Whiskers are found in many kinds of mammals, like Rodentia, Afrotheria, and marsupials. They work in similar ways, which suggests that whiskers might have been a feature in a shared ancestor of all therian mammals. Some humans have tiny muscles in their upper lip that are reminders of this ancient trait.

Artificial whiskers

Scientists and engineers have made artificial whiskers to learn more about how real whiskers work. They also use them to give robots a sense of touch. These artificial whiskers vary from simple models to robots that mimic animals with whiskers, such as ScratchBot and ShrewBot made by the Bristol Robotics Laboratory.

In non-mammals

Some animals that are not mammals have special features that work like whiskers to help them feel their way.

In birds

Certain birds have special feathers near their beaks that act like whiskers. The whiskered auklet has stiff white feathers above and below its eyes. When these feathers were covered, the auklet bumped into things more often. Other birds with similar feathers include kiwis, flycatchers, swallows, nightjars, whip-poor-wills, the kākāpō, and the long-whiskered owlet.

In fish

Some fish have long, thin feelers near their mouths, often called "whiskers." These are correctly known as barbels. Fish with barbels include the catfish, carp, goatfish, hagfish, sturgeon, zebrafish, and some kinds of shark. The Pimelodidae family of catfishes is known for its long barbels.

In pterosaurs

Anurognathid pterosaurs may have had special textures on their jaws where whiskers could have attached, though no actual whiskers have been found. Recently, special feathers were discovered around the mouths of these pterosaurs.