What Size Are Baby Rats?

When it comes to the size of baby rats, the answer is a little bit complicated. They are small and dark when they are young, and they’re also quite clean. However, the nervous system is not fully developed, so they’ll tend to be uncoordinated. Once they reach the age of three weeks, they will become more coordinated.

Rats are slightly larger than mice, but their bodies are similar. A rat’s head is significantly larger than a mouse’s, and it has a tail that is longer than a mouse’s. Rats can reach up to 40 cm in length, while mice usually only grow to be 12 to 20 cm. The size difference between a mouse and a rat will become more noticeable as the animals grow older.

Baby rats are one and a half inches long when they are born, and are hairless. In contrast, house mice and deer mice are half to one inch long when they are born. Fur begins to grow on baby rats at one week of age. At two weeks of age, their fur is short and fluffy, and at four weeks, their fur flattens.

Rats and mice have similar tail lengths, but the latter is thicker and longer. Baby mice have longer tails than rat babies, and they are often referred to as baby mice. However, baby rats’ tails aren’t noticeable at first, but as they grow older, they become noticeable.