Which statement is true about mice in the age range of 1-5 days?

• A. They are born hairless
• B. They have fur
• C. They are blind
• D. They can walk

Answer: (A)

Newborn mice are altricial and depend entirely on their mother. In the 1–5 day window, they are essentially hairless, since fur has not yet grown in. Their eyes and ears are closed, and they are too fragile to move about confidently. This hairless state is the most observable and characteristic feature of pups at this young age, which is why it’s the correct statement. It’s true they’re blind and not yet capable of walking well, but the lack of fur best captures what you’d see in a newborn during this specific timeframe.