4 January 2024

Is this horse neighing? Is the lion roaring?

No. In both cases they have smelled something interesting, perhaps a female in heat, and are breathing through their mouths and opening their airways to take in as much scent as possible into a special olfactory organ called the vomeronasal organ.

They are making a flehmen response. On Throwback Thursday, learn more and see a video in this vintage article: