Lipcurl

Flehmen or lipcurl was quite common, usually by a male to the urine of a female, especially if the female was in heat.

Sexual activity includes lipcurl, sniffing the rear or urine of another animal, courting, attempted and/or successful mounting.

The lipcurl or horse laugh (flehmen in German) may occur in response to the smell of strange manure or to a variety of other odors.

During lipcurl, odorant molecules are being aspirated into the vomeronasal organs in the roof of the mouth (Ladewig and Hart, 1980).

The male sniffs the urine or takes some into his mouth and "lipcurls" by raising his head with the mouth open and upper lip curled back.