[2] The word was introduced in 1930 by Karl Max Schneider, director of the Leipzig zoo and an authority on big cats in captivity.
[5] This response is characterized by the animal curling back its top lip exposing the front teeth and gums, then inhaling and holding the posture for several seconds.
[6] Animals that exhibit flehmen have a papilla located behind the incisors and ducts which connect the oral cavity to the VNO, with horses being an exception.
Sources of non-VOCs relevant to the flehmen response include pheromones and hormones excreted from the genital regions or urine of animals.
This study suggests there is a common element in the urine of all animals, an interspecific pheromone, which elicits flehmen behavior.
[19] Elephants perform a flehmen response but also transfer chemosensory stimuli to the vomeronasal opening in the roof of their mouths using the prehensile structure, sometimes called a "finger", at the tips of their trunks.
[citation needed] Other animals which exhibit the flehmen response include sheep,[12] American bison,[20] tigers,[21] tapirs,[22] lions,[23] giraffes,[19] goats,[24] llamas,[25] kobs,[26] hedgehogs,[27] rhinoceros,[28][29] giant pandas,[30] antelope[10] and hippopotamuses.