Don't know if this applies to llamas, but I have heard that donkeys are also good at defending sheep herds except for one small "bug". Apparently, they will defend the herd against any intruder. This includes strays which try to rejoin the herd. A fellow in southern NB had to get rid of his guard donkey as it had poor eyesight and was killing sheep left and right which had wandered only a short distance from the herd.

Anyone know if llamas kill stray sheep which try to rejoin the herd ?

BTW, years ago, I was working in northern Nova Scotia and a local town hall meeting about the coyote/sheep ( called Eastern Brush Wolves by some ) problem was being aired on radio. Sounded like a young female biologist from the government who described a plan to use bait laced with knockout pills so that the Yotes could be humanely sterilized and released. She entertained a question and you could hear an elderly gentleman state, in a rather austere English accent, "Miss, the coyotes are eating our sheep, not f***ing them."