an
investigative behavior during which an animal
elevates its
head and
curls back its upper lip. this is to detect weaker, fluid-borne
pheromones, such as those present in
vaginal secretions or
urine. curling the upper lip will close off the nostrils and allow the pheromones to enter the
nasopalatine duct. from there they travel to the
vomeronasal organ and are examined by sensory
neurons.
this behavior is exhibited most often by
males as a part of
courtship behavior, in order to determine whether a nearby
female is in
estrus and therefore receptive to
mating. however, flehmen is also sometimes exhibited by females. this could be during
sexual encounters with males, when near another female in estrus, or when introduced to new compounds such as
placental fluids or
newborn animals.