Head and tongue of twig snake (Thelotornis kirtlandi). The snake is said to flicker its black and red tongue in order to attract prey such as lizards. The primary function of a snake’s forked tongue is to collect minute chemical particles from the air. When the tongue is withdrawn back into the mouth, each of the two ‘prongs’ comes into contact with a patch of sensory cells on the roof of the mouth called the Jacobson’s organ. Sensory messages are then sent to the brain. Ibadan, May 1967.