
(from the article `perissodactyl`) Male zebras and horses follow mares in estrus. The stallion, after smelling the spot where a mare has urinated or defecated, exhibits `flehmen` (a ... ...behaviour, a regular component of which is for the male to sniff or lick the female`s urine, and afterward to raise his head slightly with ...
Found on
http://www.britannica.com/eb/a-z/f/35

A reaction to odd smells or tastes; horse curls upper lip upward
Found on
http://www.gaitedhorses.net/Articles/HorseGlossary.html

A curling of the upper lip or open mouth behavior which is a normal mating behavior in the male alpaca and llama.
Found on
https://www.encyclo.co.uk/local/22445

a behavioral response of many male mammals, esp. deer, antelope, and other artiodactyls, consisting of lip curling and head raising after sniffing a female's urine.
Found on
https://www.infoplease.com/dictionary/flehmen
No exact match found.