Lion Showing Flehmen Response. The Flehmen Response (from German Flehmen, Meaning To Curl The Upper Lip), Is A Particular Type Of Curling Of The Upper Lip In Ungulates, Felids, And Many Other Mammals, Which Facilitates The Transfer Of Pheromones And Other Scents Into The Vomeronasal Organ, Also Called The Jacobson's Organ. Photo