Can't say I have seen this behavior, but it's not winter yet. My B is very cold natured or at least she was at the end of winter last year when I got her.
Yep, it is a really common thing for males to do. You will see male dogs do this regularly when breeding season approaches as they check the urine of females to see if they are receptive. A lot of dogs generalize the behavior to something they do when they are just plain excited.
I have seen a lot of dogs AND horses do it, btw. 
My senji don't but its not uncommon. Just one more little odd behavior to entertain us
Ah ha ha ha–- Miles does this!! I think it's so funny... He does it when we're outside and he's found something wet. I always thought he was a little connoisseur who was tasting the morning dew...lol.
EL D doesn't chatter but smacks his lips.
Max would do this when he found what was probably female in heat urine on our walks. It was so funny! That was the only time he ever did it. I haven't seen Tyler do it at all. Max was neutered, and so is Tyler. Zoey smacks her lips when she's excited–usually when she's waiting for a treat.
Apache does that all the time…Marlowe will on occasion too and he's neutered.
Buckeye and Cole who I fostered did it when they first came to my house, i thought it was because they were nervous..
My female does it when she is playing hard or fighting with with other dogs (male or female) and I saw her do it once after beating up the cat we have (also a male). I've been told that females do it as a sign of sexual arousal. But I just watched (5 minutes ago) her do it after fighting with our male pup. really looking for some clarification on this.
I have seen Mica when she goes on point with her tail straight out and her front and back paws CAREFULLY matching each step chatter her jaw - It kind of goes open and shut and wanders open and shut that way. She is like an arrow waiting to fly out of the bow onto the suspected target. She never stops that behavior, either. Than she makes a mad dash for the squirrel or critter and will do doggie-ups on the side of a tree - maybe 6-8 feet up the side than down. Than shell do it again just because she has to try again. I think she is getting some really strong chest muscles. I think it might me intense excitement and anticipation.
Micas mom
