Do All Mammals Have Hair? Know Interesting Animal Body Facts For Kids!

Joan Agie
Nov 07, 2023 By Joan Agie
Originally Published on Apr 09, 2022
English sheepdog sitting in garden.

Hair or as it may be recognized as fur in the case of certain animals is a mammalian feature.

You might have come across some mammals who do not have the same amount of hair or fur on their body as compared to others but at some point in time in their life and in at least some quantity, every mammal will have hair on its body.

The hair that we see growing on the body of a human or on that of animals grows out of a pit in the skin which is known as follicles.

Mammals are found in different conditions all across the world; even marine animals including the likes of dolphins and whales have hair on their skin although it isn't as thick as some of the other mammals. Mammals are warm-blooded animals whose bodies need to stay warm.

The natural growth of hair or fur on the skin of a human or an animal acts as a coat against harsh weather conditions and helps regulate the body temperature.

What mammal does not have hair?

Some mammal species have undergone an evolution in such a way that they do not have the same quantity of hair on their skin as other mammals. Ranging from everyday pet animals to some majestic marine animals, there are some unique mammal species that lack the natural growth of hair or fur on their body parts.

Animals like dolphins, porpoises, and whales all fall under the category of cetaceans marking the potentially largest group of animals who lack a thick layer of hair on their skin, however, they do have some hair at some point in their lives.

These marine animals have adapted in such a way that they do not need hair for insulation; instead, they use blubber for the same purpose.

The largest land mammal, the African elephant barely has any hair on its body primarily due to the fact that it lives in a climate where it doesn't need to retain any heat.

Walruses are another mammal whose bodies have thick blubber instead of hair.

Walruses have a red-brown colored fur which is pretty short and this coat isn't significantly visible. It is the whiskers of the walrus that do not make it seem completely naked.

There are some pet mammals as well who do not have hair on their body, especially certain species of hairless dogs such as the American hairless terrier, the Mexican hairless dog, and the Peruvian hairless dog.

Humans seem to be quite fond of adopting these dog species as they do not have the issue of shedding their hair and are hypoallergenic too. At the same time, as these dogs do not have hair on their body, they are pretty sensitive to cold weather and sunshine.

Apart from dogs, the other most common pet mammal is a cat.

Unsurprisingly, there is a cat species as well that lacks any thick layer of hair on its body, and it is called the Sphynx. Sphynxes are cats that have only a minimal amount of hair on their body which makes their skin seem soft.

Some of the other animal species which barely have a layer of fur on their body are hippopotamus, naked mole-rat, skinny pig, and babirusa.

Why do mammals have hair?

Mammals have evolved in such a manner that they require a high body temperature in order to survive. For humans or animals to maintain this high body temperature, their body needs to stay warm, this is where the hair comes into play.

Fur and hair on the body of animals act as insulation when they create a layer that protects the skin of the animal's body from harsh winter conditions outside.

We have seen that different animals have varying lengths of fur and hair on their skin, and this is largely dependent on the environment the mammals live in.

Along with the thickness of the fur, the oiliness of the fur plays a pivotal role in determining how effective it is in protecting the animal from cold conditions. The thickness and the oiliness of fur are directly proportional to the amount of heat trapped inside the coat in protecting the skin of the animal from the cold.

Additionally, not only does the hair help in trapping heat but also helps keep off the sun from the skin of the animal.

Different animal species often have the same amount of hair on their body but the fur of one seems thicker than that of the other because the hair of one grows longer than that of the other.

Sheep walking on a steep mountain.

Are mammals the only animals that have hair?

Hairs are dead substances or cords which are composed of a substance called keratin. You might have come across similar-looking material which may seem like hair on animals that aren't mammals but in reality, these substances aren't actually true hair.

For instance, the strands that we see on the body of a spider seem like hair but are actually a sensory part of the spider and the spider would physically get hurt if it is cut from its body.

Mammals happen to be the only kind of animal type in the world that have true hair on their body. It is one of the features which distinguishes mammals from other animals in the world.

Whether it is an entire body covered with hair such as that of some dog species or marine mammals which barely have any presence of hair on their bodies, each and every mammal has some amount of hair on their body at some point in their life.

What animal has the thickest hair?

One of the less popular animals in the world, the sea otter happens to have the thickest fur in the world as its body contains around 600,000-1,000,000 hair follicles per square inch.

Interestingly, unlike most other mammals living in aquatic conditions, sea otters do not have a layer of blubber to trap heat.

Their fur is water-resistant which helps them stay warm. At the same time, these animals spend a significant part of their day undertaking grooming activities in order to keep their fur in good condition so that it can trap air and heat next to the skin and keep the animal warm under harsh conditions.

It is not known which animal grows hair the fastest, however, when it comes to animals with the most beautiful hair in the world, there are quite a few such as the Afghan Hound, Lhasa Apso, Norwegian forest cat, and more.

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Written by Joan Agie

Bachelor of Science specializing in Human Anatomy

Joan Agie picture

Joan AgieBachelor of Science specializing in Human Anatomy

With 3+ years of research and content writing experience across several niches, especially on education, technology, and business topics. Joan holds a Bachelor’s degree in Human Anatomy from the Federal University of Technology, Akure, Nigeria, and has worked as a researcher and writer for organizations across Nigeria, the US, the UK, and Germany. Joan enjoys meditation, watching movies, and learning new languages in her free time.

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