how big can rats get
Size. The average body length of adult rats is 9 to 11 inches, plus a tail of 7 to 9 inches, according to the American Fancy Rat and Mouse Association. Your pet rat could grow to be up to 20 inches long from nose tip to tail tip.In rare instances, an adult male pet rat might grow to weigh 2 lbs.The rat's body can compress to allow it to access small spaces -- an opening the size of a quarter in your wall or near a pipe will allow a rat to enter your home.our pet rat could grow to be up to 20 inches long from nose tip to tail tip. In rare instances, an adult male pet rat might grow to weigh 2 lbs. The rat's body can compress to allow it to access small spaces -- an opening the size of a quarter in your wall or near a pipe will allow a rat to enter your home.