hi we feed ours. almost anything, including frozen peas thawed and removed from the shells. another awsome food ours like is small earth worms,pretty cool to see them gobble up those worms. About keeping more than one in a tank,in my opion is not a good thing at all. one will become the dominant one and possibly kill the other two in time. It seem that the peaple that sold you these should have told you that! good luck.