get some boilers if you can mate they grow very fast as long as you give them plenty of food and scraps but some times they collapse as they get to heavy to quick.
years ago my mate slipped in on a rabbit my old bitch was running and his dog ended up with 4 broken ribs and a punchered lung.never lived to see another day and it showed protential so i wouldnt run 2 together mate but thats my opinian
rats are classed as nervivours mate which means they dont like new objects and could take a couple of weeks to get used to them.we tery peanut butter,chocolate or prawn cocktail crisps as the stronger the smell the more tempting it is