Why Do Rats Have Tails?

Rats are rodents that are medium-sized and are characterized by their long tails. Rats and mice look very similar, and one of the only ways to distinguish them is by their size. Rats are larger than mice. There are two common species of rats; black rats and brown rats. Both have long tails, and I have often wondered what they use this for.

Rats have long tails, which help them aid in balancing. They also use their tail for thermoregulation. Rats are unable to sweat, and their tail allows them to lose heat from their body.

While rats are well known to be invasive and a great nuisance, the other notable thing about them is their long tails. The rat’s long tail is a feature that has often attracted the interest of many scientists. Scientists conducted various studies to determine if this tail is functional. Well, there is a lot they discovered. I have shared all the details in this article.

Rats are thought to be natives of northern china but have spread throughout the globe except for Antarctica. In North America, both black and brown rats are common and inhabit almost every region. 

Cougars can be found in North America.  Find out where in this article I wrote

Rats can be described as opportunistic and the masters of adaptation. For one thing, they can live anywhere, ranging from forests, woodlands, suburban areas, urban areas, and even deserts.

Rats prefer to live close to humans, even in their houses. This is due to the availability of food, water, and shelter.  

Ever wondered if bears have tails? Find out here in an article I have written.

When Does a Rat’s Tail Grow?

Typically, a rat is born with its tail, which grows when the young one is still in its mother’s womb. When you take a look at the tail of a rat, it seems very simple. People will think it’s just a tail. However, it is quite an intricate part of a rat’s body.


The tail is an extension of the vertebral column of a rat. In most animals, the vertebra is located on the back and remains on the inside. There is a good reason why the rat vertebral column extends right into the tail and projects outside.

There are three layers in the tail. The innermost layer is the core, which is made up of vertebra or bone. Tendons surround this core layer. On the outside, there is a layer of hairless skin. In between the tendons, various blood vessels run through the entire tail. 

What is the Purpose of a Rat’s Tail?

The tail performs two primary functions, namely, thermoregulation and balance. The tail is vital for the survival of this animal, and is one reason it can thrive in different environments.

Mammals use their tails in many ways.  Find out more in this article I wrote


The tail is a thermoregulatory organ. The rat loses heat from its body through the tail. This is vitally important because rats are unable to sweat. The blood vessels in the tail work to control the body temperatures of the rat. This means that the blood vessels can easily adjust to cold and hot weather conditions.

During hot weather, the temperature of the rat’s body will rise. This prompts the vessels in the tail to dilate, allowing a lot of blood to the tail. The blood will lose most of the heat through the layer of skin on the tail. The blood that now flows back to the body will lower the temperature to cool down the rat.

When the temperature is cold, the blood vessels in the tail constrict. Therefore, there is less blood flowing towards that region of the animal. The rat’s blood is kept in the body’s interior, and this retains its body heat. By doing this, the animal can regulate its temperature and can keep warm.

If you want to know which species of bat lives in Maryland then this article is for you


Aside from thermoregulation, the other function of the tail is to maintain balance. If you have ever seen how a rat can walk along ropes, fences, and wires, it is the tail that helps. This animal’s tail is the secret to its perfect balance, especially on narrow surfaces. 

Balance – Not the best example

When a rat is walking along rope, wire, or cable, their center of gravity must be directly above the cable. This prevents it from rotating on top of the cable. In this case, the tail works to increase rotational inertia so that the rat does not end up revolving around the rope. 

Furthermore, rotational inertia enables this animal to adjust its center of gravity easily. With this, the rat can maintain the perfect balance on various surfaces.

Why do mammals have tails? Find out here.

How Does The Rat’s Tail Help With Predators?

The rat is such a small creature, which means that it has many potential predators. The rat does not have much of a defense mechanism, and it is quickly turned into a meal by various carnivores.

The tail is part of its survival and defense mechanism. Rats will use the tail to distract predators. The rat would rather sustain injuries on the tail rather than on the body.  It is also easier for the rat to escape should a predator catch the tail.

At times, a small part or even the entire tail is cut off by a predator. In this case, the rat can still survive without it. The tail is also used to threaten an enemy. When a rat comes face to face with a rival, it lashes out the long tail.

Ever wondered why whales slap their tails?  Find out the reason here

Does a Rat’s Tail Grow Back?

A rat’s tail does not grow back if it is accidentally amputated. The tail itself is quite delicate and can easily be cut off if the rat pulls away hard enough when the tail is caught.

The tail is an extension of the vertebral column, and this part of the body cannot regenerate. If a part of the tail is severely injured but not completely pulled off, that particular portion will gradually die and eventually fall off. The remaining part heals with time and dries out.

Can a Rat Survive Without its Tail?

A rat can live a normal life even without its tail. Many times, rats get their tail amputated by people or predators, but they can still survive. 

Although able to adapt, a tailless rat is more at a disadvantage than one with a tail.  A rat without a tail will not survive long in the wild because it will be one easily susceptible to predators, due to their lack of balance.

Additionally, one primary function of the tail is to regulate a rat’s body temperature. A rat without a tail will not lose body heat as effectively as those with a tail. 

Since it lacks a way to regulate temperatures, the rat will have a higher body temperature. Their high body temperatures will take much longer to cool down.

A rat may be able to live without a tail, but it will be prone to accidents. This is due to the lack of proper balance. Most of these are challenges that come with the amputation of the tail. However, most rats can adapt and find ways to survive quickly.

There have been attempts to breed pet rats without tails, but most pet owners do not like rats without tails. These attempts have also been met with objections citing all the health complications that come with the lack of a tail.

If you want to know why mammals have tails (and we don’t) then click here

Why Do Rats Not Have Fur on Their Tails?

One noticeable thing about a rat’s tail is the fact that it’s hairless. The tail does not have fur on it for two good reasons. 

The first reason is to allow proper and fast heat loss. The tail is meant to control body temperatures. With fur on it, the heat loss process would be much slower and less efficient. The fur on the tail can make the rat overheat very fast.

The tail is also used for grasping and balancing on surfaces. It would be more difficult for a rat to use its tail to hang on objects if the tail had fur. A rat can climb onto various surfaces easily because of its hairless tail. The tail offers a firm grip on objects.

There are 20 species of mammals in North America that are currently endangered.  Find out what they are here

Why Do Rats Have Long Tails?

On average, the length of a rat’s tail is almost equivalent to its body length. Rats have longer tails when compared to other rodents. The long tail increases the surface area for maximum heat loss.

On occasions, a rat may curl the tail around its body, especially during the cold weather. This helps to keep it warm. It is believed the tail’s length is determined by the climatic conditions of the rat’s habitat. Rats in hotter regions tend to have longer tails so that they can lose heat easily.

The tail of a rat may also be longer to increase balance in certain environments. A rat wraps its tail around objects when climbing. A longer tail is more effective and allows for a firm grip. The rat uses its tail to lift itself and reach up to higher surfaces when searching for food.

Are All Rats Born With Tails?

All normal rats have tails. However, there are some rare cases where a rat is born without a tail. This is often linked to gene mutations and abnormalities. Some offspring born without tails only survive for a couple of days or die at birth. Others make it to adulthood but still face many health conditions. The major challenge is usually regulating their body temperature. 

Bighorn sheep are synonymous with North America.  Find out where they live here

Bryan Harding

Bryan has spent his whole life around animals. While loving all animals, Bryan is especially fond of mammals and has studied and worked with them around the world. Not only does Bryan share his knowledge and experience with our readers, but he also serves as owner, editor, and publisher of North American Mammals.

Recent Posts