It's not just the llama who likes to beat up on poor, defenseless sprinklers. The alpacas do it too. I put out the sprinkler this morning, and the alpacas went Office Space on it. They kicked it until it flipped over, then cushed down in a circle around it in their chosen spray-intensity.
After a half an hour, I went out and flipped the sprinkler right side up again (rearranging the alpacas in the process). I hadn't made it back to the front door before Hercules had kicked it sideways and was standing over it with the spray splashing up under his tummy.