Question: How does a snakes tongue work and how does it know what molecules it is picking up

Melissa Upjohn answered on 20 Nov 2025:

You probably know that unlike humans, a snake uses its tongue to detect smell rather than taste. The molecules which are collected on the tongue are transmitted to the Jacobsen’s organ in the roof of the mouth as the tongue comes back into the mouth (some other animal species also have a Jacobsen’s organ but in humans although it may still exist it doesn’t ‘function’ in the process of detecting smell or taste). There are lots of different types of smell detecting nerve cells (neurons) within the Jacobsen’s organ, each of these different types is structured in a way which means that it can only collect one kind of molecule, so when the neurons which have collected molecules send messages to the specialised part of the brain which focuses on smell, the brain interprets the pattern of neurons from which it has received information to recognise what produced those molecules.