flehmen

/ˈfleɪmən/
noun
  1. A behavior in animals, especially mammals, where they curl back their upper lip and inhale to better detect scents or pheromones.
    • Lions often show a flehmen response when investigating a new smell in their territory.
    • The zookeeper explained that the cat's flehmen helps it analyze chemical signals in the air.
    • The horse performed a flehmen after smelling the mare's scent.