We often see snakes wagging their tongues. But why do these feared reptiles like sticking out their tongues? Well, when a snake does that, it’s “tasting” the air to “smell” and detect what’s around.
It turns out even though snakes lack ears and have eyesight that is ordinary and not particularly impressive for their reputation as cold-blooded hunters, they pack their own remarkable set of detection “gadgets”. One of these is the Jacobson’s organ, (also known as the vomeronasal organ) used together with the snake’s tongue.
Here’s how it works. When a snake sticks its tongue out, receptors on the tongue pick up tiny chemical particles drifting in the air. All sorts of minuscule particles, chemicals and scents drift in the air: an endless list of water droplets, hair and fur, fibres, pollen, and so on. Sunlight pouring into a dark room gives us a glimpse into this phenomenon – at least with those particles that are large enough to be seen by human eyes when they are together.
For snakes, this ability is much more enhanced to the extent that they are able to “smell” the air with their tongues by picking up these particles and identifying them.
In the roof of a snake’s mouth is the Jacobson’s organ, with two grooves into which the snake’s forked tongue fits. When the tongue makes contact with the Jacobson’s organ,
the chemical information of the particles that the tongue picks up, is gathered by the Jacobson’s organ and sent to the brain, which then processes the information, helping the snake identify the particles and accordingly, the creature or object associated with it.
So before a snake actually sees you in the wild, a breeze blowing and broadcasting tiny fibres from your clothes can make the snake aware of human clothing in its vicinity …