Why your cat’s tail become big puffy every now and then?

Cat named Loki with a puffy tail
Cat named Loki with a puffy tail.
Photo: Attribution Some rights reserved by jon_a_ross

Have you ever seen your cat being startled by something and his tail becoming puffy? Usually it may stay this way for several minutes, especially if the cat is frightened by a noise, but is not able to tell what was the source of it. Also, your cat’s tail may be accompanied by upward hair on the hid part of his back. Why is he doing so? Why is your cat’s tail big and puffy?

Have you ever heard a word goose bumps? Those are small bumps on your skin that usually appear when you are cold or, scared like a cat. They look like a skin of plucked goose, so this is where they got their name of.

They appear on your skin due to a reflex called “piloerection” or “arasing”. This reflex is a response to cold and fear as we already stated, but may also be present during pleasure, nostalgia, euphoria or sexual arousal.

So, what is the benefit of piloerection reflex? It makes the hair on the skin stand. While we, humans do not have very much hair on our body, for animals, like cats or dogs it makes a huge difference.

For example, if the animal, let’s say, a cat is afraid of something, hair on his back, and the tail stand, making him appear larger, and, if lucky, will scare the intruder away.

While the above is the most common why cats puff their tail because they are scared, there are other cases when hair crawling becomes beneficial.

Giving insulation is another well known benefit of this reflex. If the hair stands, it traps the air between layers of hair and skin, and thus it works as heating insulation, similarly like a rock-wool works on the walls of our homes.

We know humans always have goose bumps when they are cold. Unfortunately, it makes no insulation for us. Cats, however, benefit of it greatly, as they have a very thick coating, while puffy tail, most often is occurring due to your cat being scared by someone or something. You can find more information about calming a fearful cat here.