Honestly, I think a llama would run the other direction. I take care of a small herd of 5. They keep 50 sheep with them in the summer. I don't see where their very defensive. They don't even hang out with the sheep. I've seen coyote circle the field & the llamas are no where to be found. The worst they do is burp & spit. Maybe I just haven't seen that side of them yet. I think you'd be better off raising an Emu to protect the flock. Or get a dog.