After about twelve days , they begin to open their eyes and explore their environment .
Babies are born about 13 mm ( 0.5 in ) long with their eyes closed , and a thick undercoat of fur .
After about twelve days , Babies begin to open Babies eyes eyes and explore their environment .
Babies are born about 13 mm ( 0.5 in ) long with their eyes closed , and a thick undercoat of fur .