Many animals have whiskers. From domesticated pets to marine mammals, whiskers can be found on many different species, and they have lots of interesting uses.
Animals use whiskers to navigate in the dark or low visibility and help decide if they can get through small gaps. Whiskers are used when hunting, such as marine mammals that can detect movements in the water or coyotes detecting motion in the air current. Whiskers are also used to communicate with others, such as when a dog is nervous or threatened.
Whiskers are vital for several aspects of daily life, including hunting, navigation, and communication, but not all animals use their whiskers in the same way.
Are Whiskers Hair?
Whiskers, or vibrissae, are body hair typically found on the muzzle and above the eyes. Only mammals have whiskers. Other animals such as lobsters and catfish have a variation of whiskers called barbels, but they are formed of fleshy tissue rather than hair.
Mammalian whiskers grow from a hair follicle with blood vessels and nerves. Like normal body hair, whiskers will occasionally be shed and regrown. Whiskers are longer, thicker, and more rigid than body hair, as the purpose is different.
Whiskers are a sensory adaptation as an extension of an animal’s vision, but not all animals use their whiskers in the same way.
Rabbits and hares use their whiskers predominantly to negotiate burrows. They use their whiskers to determine if a hole is too small to fit through, which prevents the animal from getting stuck. Rabbits and hares also use their whiskers to investigate objects that are difficult to see due to the placement of their eyes. They cannot see anything that is directly in front of them very well.
Like rabbits and hares, cats also use their facial whiskers to navigate their surroundings. Cats are very flexible and can fit through tiny spaces. Their whiskers help them decide if a gap is too small to fit.
Cats also have whiskers on their lower legs, near their ankles. It is believed that cats use their leg whiskers when they climb fences or trees. As an object brushes against the whiskers, it causes the whiskers to vibrate, sending messages via the nerves to the cat’s brain.
Both dogs and cats can navigate a dark space without bumping into walls. As air hits solid objects, the air currents will change. This can be sensed via an animal’s whiskers, which help them navigate in the dark even if they have limited vision.
Research from the University of Sheffield found that rats use their whiskers similarly to how humans use their fingers. It was found during the study that rats have much greater control over their whiskers than previously thought.
In new environments, rats move slowly and use broad sweeping movements with their whiskers to detect obstacles like walls and gaps between objects, plus investigate surfaces such as the floor. As the rats became accustomed to their environment, they moved more quickly. Their whisker’s movement changed to a forward position to detect obstacles ahead of them to avoid collisions.
In dark environments with many obstacles, rats moved their whiskers further forward from their face and moved at a much slower pace, reacting to the increased danger of potential collisions. This is the same behavior of humans using their hands and fingers to navigate environments with little or no light. We are aware of the obstacles in our own homes and can move more quickly, but in a strange environment, you would move much more slowly and use your hands and fingers held in front of you to prevent you from walking into things.
When it comes to finding food, marine mammals are well equipped. When the visibility in murky water is low, animals like seals, walruses, and manatees can use their whiskers to sense the movement of their prey.
Seals will position their whiskers further away from their face. This allows them a better position to sense disturbances in the water made by nearby fish. A marine mammal has such sensitive whiskers that they can follow these disturbances to track their prey, even if visibility is less than 1 foot.
Seals have a different whisker shape than other mammals. Most have straight, rounded whiskers, but seals have wavy whiskers. Experts believe these irregular shapes help keep the whisker steady as the seal swims.
Experiments have shown that a seal can detect a fish from 100m away, and it is thought that their whiskers are the main reason. Their ability to detect and track changes in water current is a huge advantage when hunting in murky water.
It is not just marine mammals that have adapted their hunting technique using their whiskers. Many land mammals do this too. North America’s coyotes and foxes use their whiskers to detect changes in the air current, informing them of movement close. Predators can also use their whiskers to determine when to strike their prey based on air movement. They can follow changes in the air current much like they would use their nose to follow a scent trail.
Cat owners can see how sensitive their pet’s whiskers are by watching them eat. If you have a cat who uses a deep bowl, you may notice that they take a mouthful of food, then lift their head away from the bowl to chew. This is because their whiskers brush against the sides of the bowl and can overwhelm a cat’s nerves along the sides of its face.
Cats favor flat, shallow bowls because their whiskers do not touch the bowl while eating to remain in the same position. This is much more comfortable and less stressful.
Whiskers are not just useful for navigation and hunting prey. Many animals also use their whiskers to communicate. Dogs, for example, can display their mood via their whiskers. An alert dog engaged with its environment will hold its whiskers upright. In contrast, a nervous dog will keep their whiskers flat to its face. If a dog feels threatened, it will flare its whiskers and then hold them forwards, pointing toward the perceived threat.
This reason, along with the other uses of whiskers, is why veterinarians and behavioral experts do not recommend trimming your dog’s whiskers. They are highly sensitive, and cutting the whiskers to a short length can easily disorientate your dog as they cannot interact as well with their surroundings.
There is a scientific belief that specific mice engage in barbering, or whisker nibbling, to display dominance. The dominant mouse will chew the whisker tips of a subordinate group member. This behavior is typically observed after a group hierarchy has been established. It is unknown if there are other reasons why dominant individuals will chew the whiskers of subordinate group members.
Whiskers have many different uses, but there are many more interesting facts about whiskers that most people do not know.
- Monotremes (egg-laying mammals) and humans are the only mammals not to evolve whiskers.
- Each whisker grows from its hair follicle, rooted much deeper than body hair.
- Female cats will nibble the whiskers of their kittens until they are short. It is believed they do this to prevent their kittens from wandering, as they cannot navigate well without their whiskers to sense their environment.
- Whiskers shed just like normal hairs and will grow back, but at a slower rate.
- Whiskers change color with age. An animal with dark whiskers will develop pale grey or white whiskers as they get older. Those with pale whiskers will grow darker whiskers in later life.
- Cats have four rows of whiskers on each cheek, while dogs are varied in number and arrangement.
- Many animals’ whiskers will grow as long as their body is wide. This is especially useful for navigating tight spaces to prevent getting stuck.
- If a cat is twitching her whiskers, she has spotted something interesting. Cats and other predators will twitch their whiskers during a hunt as they try to determine the best time to strike.
- For cats, almost 40% of their brain is wired to react to areas where whiskers grow. Each whisker has its spot on the cat’s brain.
Whiskers are not just cute facial hair; they are far more essential than simple appearance. Many mammalian species would struggle to communicate, hunt or navigate their environment without whiskers.
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Bryan Harding is a member of the American Society of Mammalogists and a member of the American Birding Association. Bryan is especially fond of mammals and has studied and worked with them around the world. Bryan serves as owner, writer, and publisher of North American Nature.