Rats Sense of Smell
A rat’s sense of smell has the ability to detect odors within the environment as well as pheromones that are related to the emotions and chemicals of other rats. It is almost like they have two different senses of smell. As they breathe through their nose, the air goes over a patch of skin in their nose that is loaded with receptors and olfactory neurons. These are tipped with cilia and the smell particles bind to these cilia and they trigger a response within the brain. Throughout a rat’s life, they will encounter different scents and their brain triggers a particular response to those smells.
They have a secondary organ, so they can sense the smell of pheromones. These pheromones represent various emotions and chemical changes (such as a female going into estrous) in other rats. This organ is called the vomeronasal organ and it is set in a space in the lower part of the nasal passage, alongside the septum. As they sniff and taste, smell particles dissolve and make their way into this organ. It detects pheromones that are excreted by glands and are present in the droppings and urine of rats as well. These pheromones are detected by other rats of the same species.