Elk Licking His Chops

Are there any hunters or wildlife experts on here? I was walking a trail alongside one of the lakes at the Wichita Mountain Wildlife Preserve when this guy rose up out of the tall grass and wanted his picture taken so I obliged and we did a thirty-minute or so photoshoot...but I was just wondering if anyone can tell me what it means a big ole elk looks you dead in the eye and starts LICKING HIS CHOPS!! I mean, these guys are vegetarians, aren't they?? LOL