How do snakes smell with their tongues?

Snakes do have nostrils, but their main sense of smell comes from the vomeronasal organ, also called Jacobson’s organ. Each flick of the tongue picks up tiny chemical particles from the air and ground. When the tongue is drawn back in, its tips deliver these molecules to two openings in the roof of the mouth leading to the organ. Because the tongue is forked, each tip samples a slightly different spot, helping the snake tell which direction a scent is strongest. This lets snakes follow prey trails and find mates.