Wildlife SOS introduces a new series “Things You Didn’t Know About” that explores fascinating and lesser-known facts about various species. Our writers will spotlight one aspect of the wild, unveiling its unique characteristics and role in the ecosystem. Did you know that some animals can release chemicals as messages for their species? In this feature, we look at the organ that can unravel information hidden in these chemicals — the Jacobson’s organ.

We now know about the five primary senses of animals: sight, hearing, taste, touch, and smell. What is not commonly known to many are the several extraordinary abilities of certain wild species such as echolocation, magnetic field detection, and the power to identify chemicals in their surroundings. Researchers have found out that many animals use what is known as a Jacobson’s organ to sense traces of chemicals that are found in their environment. 

Named after Ludvig Levin Jacobson, the anatomist who discovered the organ in 1811, Jacobson’s organ comprises a sensitive set of nerve cells that can analyse chemicals present in the scent captured by animals. This is why the organ is recognised as a chemosensory organ — it can detect chemicals called pheromones that are produced and secreted by members of the same species, by their prey and even by their predators. These pheromones also carry messages that can help another from the same species identify a potential mate or possible danger.

Reptiles, amphibians, and some mammals possess Jacobson’s organ, which is also known as the vomeronasal organ as it is a strong partner of the olfactory system. For reptiles, the Jacobson’s organ is located on the roof of the mouth, to which the tongue transfers the scent collected. For amphibians and mammals, this stimulating organ is located in the nasal cavity.