Brown Rats have a coarse and usually brown or dark grey fur, with lighter underparts, and an all dark tail.

Their feet and inner ears are pinkish, and they can have a body length of up to 25 centimeters, and an equally long tail.

They prefer to live where humans are and are hence found only in ports and large cities. They are poor climbers, but dig well and may excavate wide-ranging burrow systems.

They are thought to have originated from northern China, and spread to most parts of the world. Today, they are the most successful mammal on our planet.