i just got a smaller rat, maybe 6 weeks old. i would like to house him in the cage that my other 3 larger males are in, will the larger rats kill him? i have the smaller rat in a pet carrier inside of the larger enclosure because i read that its a good idea to introduce them without being able to fight and i dont have any other enclosures due to already having close to 30 rats. what is the best way of going about this with my little guy being considerably smaller?