Flehmen

 WORD OF THE DAY

flehmen / noun / FLAY-mun

Definition
1: a mammalian behavior (as of horses or cats) in which the animal inhales with the mouth open and upper lip curled to facilitate exposure of the vomeronasal organ to a scent or pheromone

Examples
"Flehmen, sometimes also called the Flehmen response or the Flehmen reaction, is actually a way of smelling or scenting the air. It's not peculiar to horses: other ungulates exhibit the response, as well as cats, elephants, and bats. Lifting the upper lip gives them access to the vomeronasal organ on the roof of their mouth, which contains chemoreceptors that help them find mates and investigate other smells in their environment."
 — The McClusky (North Dakota) Gazette, 10 Sept. 2020

 Did You Know?
Flehmen comes from German, in which the word applies to animals and means "to curl the upper lip."
The German source of the English word is a verb, and it is used, infrequently, as such, as in "the horse flehmened."
More often, the English verb form is a gerund: "the horse's flehmening."
Flehmen is sometimes capitalized in English because German nouns are capitalized; however, the English word tends to be lowercase.