Baby Mouse, Rat, or Vole Found Alone Outside of a Nest
Though they are helpless at birth, rats, mice, and voles grow up quickly, and are usually independent by 3-4 weeks old. Babies remain in the nest, nursing from their mother until their eyes have opened and they are fully furred. Babies whose eyes are still sealed shut or who are healthy but do not avoid capture would normally be in their nest at all times.