Flehmen or lipcurl was quite common, usually by a male to the urine of a female, especially if the female was in heat.1970, Journal of Mammalogy, page 279:
Sexual activity includes lipcurl, sniffing the rear or urine of another animal, courting, attempted and/or successful mounting.1980, Desert Bighorn Council, Transactions - Volume 24, page 18:
2 more examples
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.1980, Proceedings:
During lipcurl, odorant molecules are being aspirated into the vomeronasal organs in the roof of the mouth (Ladewig and Hart, 1980).1984, Journal of animal science - Volume 58, Issue 1, page 507:
lipcurl
verb
Etymology From lip + curl.
1
To perform a lipcurl.
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.1984, Journal of animal science - Volume 58, Issue 1, page 507: