I've put this in here as it relates to seasons and I guessed the most knowledgeable people on such things are those that breed.

I have two bitches, both currently in season, one on day 8 the other (eldest) is on day 5.  The eldest one chatters her teeth shortly after sniffing the younger bitches vulva.  I know males often do this around in season bitches but just wondered how common/usual it is for bitches to do it?  The eldest has always teeth chattered when the younger is in season although this is the first time their seasons have matched up.

Mine do it all the time and I have 3 Granny, daughter and Grandaughter. They all clean one another as well. (and have comunal humping sessions ! :-D )
Aileen

Oh yes, they like cleaning each other, although the youngest isn't allowed to clean the oldest very often and the elder is often the humper, the privaledge's of age eh?

Nice to hear mine isn't the only chatterer, I was just curious if there were others out there!

*laughing* my 5 year old NEUTERED male dog (lost his bits at 18 mths) was teeth chattering a few weeks ago, never seen anything like it - he's never done it previously. Nose was superglued to the ground and he was chattering and dribbling for a full ten minutes or more. I can only guess someone round here is walking an in-season bitch. My neighbour was outside washing his car and he could see what my lad was doing, he was laughing so much, I guess he'd never seen anything like it before either!

My girls are like Hannibal Lector with a nice glass of Chianti and the boys are even worse!

We also have mega teeth chattering in our house when my two young girls season, it's major between them and minor between my other older 3 speyed girls but they still do it to a lesser degree.

I may be wrong but I think it is how animals pull a particualrly pleasant or interesting smell over the smell receptors in their nose.

You are quite right with that Pinky, it's called the vomeronasal organ and in dogs is located between the upper mouth and nasal passages. Dogs often lick interesting scents to carry them to this special receptor, which is believed to be sensitive to phermomones. Other animals have the same thing, you often see a reaction in cats and horses.

oooh, so that's why, very interesting thanks, I love knowing the "whys?" !

one of my girls chatters when she gets excited at meal times.

My Rhuari starts wee tasting[behaves like one of those wine tasting experts you see on TV] about a week before the girls come into season, I then know I need to check them with a tissue first thing each morning before they have been for a wee.