There are many animals on Earth, and many of them are round. You may think of them as cuddly balls, but their shape actually helps them survive in nature. Here are some of the roundest animals in the animal kingdom.

At the top of our list is the puffer fish family (Tetraodontidae), also known in Bengali as potka fish. This round fish can take on the shape of a ball to defend itself.

It does this by drawing large amounts of water into its elastic stomach. This makes it look far less appealing, and in that shape the fish also looks hard to eat.

These ball-shaped fish may be pleasing to look at, but they should never be touched. Most of the more than 200 species of puffer fish contain a poison called tetrodotoxin, which is 1,200 times more toxic than cyanide.

In Spanish, the word armadillo means "little armoured one". There are 21 kinds of armadillo in the world, and the smallest of them is the pink fairy armadillo (Chlamyphorus truncatus), which measures between 9 and 12 centimetres in length.

Source: BBC Bangla. First published in Bengali on The Agro News.