flehmen

American  

[fley-muhn] / ˈfleɪ mən /

noun

1. Also called flehmen response, flehmen reaction. a behavioral response of many mammals, especially deer and other artiodactyls, felines, and horses, consisting of raising the head and curling the upper lip to aid the sense of smell by increasing the flow of air through the nostrils and exposing the auxiliary olfactory organs: often a response to the detection of pheromones.

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verb (used without object)

1. (of deer, horses, and many other mammals) to raise the head and curl the upper lip to aid the sense of smell by increasing the flow of air through the nostrils and exposing the auxiliary olfactory organs.

Etymology

Origin of flehmen

From German Flehmen, noun use of infinitive: “(of a domestic ungulate) to curl the lip”; compare dialectal (Upper Saxony) flemmen “to look spiteful”; further relations unclear

Example Sentences

See Examples For:

flehmen

As the same urine was presented again and again, the flehmen response became less frequent.

From Science Daily ● Sep. 20, 2026

Researchers also examined the flehmen response, the characteristic open-mouthed expression often seen when cats investigate certain odors.

From Science Daily ● Sep. 20, 2026

Some mammals make a face called flehmen to direct air to this organ.

From Textbooks ● Jan. 1, 2015

Next time you see your cat smell something and hold its mouth open with upper lips curled and teeth exposed in what is called the flehmen response, you can bet something tweaked its Jacobson’s organ.

From Slate ● Aug. 25, 2014