We used to live on this Slaty-backed Gull until it died. We love sick birds--when they're feeling crappy, they forget all about preening and we can multiply like flies, so to speak, till you can actually see us crawling around in the short feathers around the face. (We give meaning to the term, "feeling lousy!!") Unfortunately, sick birds like this one don't last too long, but we reproduce, making lots and lots of baby lice so when the bird finally keels over and we sense its body temperature dropping, we can jump ship and find us a new one to pester. Sometimes we luck out and find one that's already too sick to preen, and sometimes we manage to transfer some of the germs from the dead one to the live one, giving us another cushy home for a long time. But usually we're stuck on some healthy one who scratches or bites us off. Oh, well. You stay in your dog-eat-dog world. We like our louse-eats-bird world just fine.