we got a bp a few months ago and then we decided to start breeding rats for the bp. we starting out small got a male and a female, then once she has her litter we will get another female and mate her. the two we got now if they are playing around they sing to each other, if you pick one up it chirps sqeeks and make all types of sounds, the other day i picked up the male and he grunted like a little pig. me and my wife have had rats as pets before but none of them have never made sounds like this and the sounds are all the time. its like they sing to each other. and they talk at you when you're at the cage.