Well the reason these lil guys are here is because if youre a lvl 50 you cant bo bothered to fight to the death with another lvl 50 so you go and eat a lvl 35 rat mmmmmmmm
These rats have been consuming and living off of the remains of dragons. Think about it, they are eating the most magical and powerful "food" in all of Norrath. No wonder they have "evolved" into such uber rats! I think it is hilarious!