Llamas are guard animals and emit a warning call that is really hard to describe. There's not really anything to compare it to.... Domino is checking out Skipper to make sure he's not a predator.
Apparently Spud doesn't care one way or the other.
We have taken the llamas backpacking into the wilderness but not this summer. I doubt they mind. They seem pretty happy to be pasture llamas.
You can check out other interesting living beings at Camera Critters.