Comprehensive Overview of a Rat’s Sense of Smell

As is the case with many animals, rats depend on their sense of smell not only to accomplish tasks associated with day to day living but also to protect themselves from threats that can exist in the environment around them. In addition, with rats their sense of smell plays an important role in their reproductive processes. Finally, through their sense of smell, rats are able to detect atmospheric changes as well. They are capable of making some basic predictions about upcoming weather changes. On some level rats can fairly be said to have three distinct senses of smell.

The Basic Sense of Smell of a Rat

Rats have a comparatively keen sense of smell when it comes to detecting scents associated with day to day living. This particularly is the case when contrasted with many other mammals. For example, rats are able to detect potential food sources from a rather considerable distance. Because rats depend on foraging for food as a means to survive, the reality that they are able to identify through smell food sources from a distance proves to be vital to their survival.

If a rat is able to gain access to the basement of your home and you’ve left a bowl of dog food on the floor somewhere on an upper level for your pooch, a rat is likely to be able to detect its presence through its sense of smell. There is also evidence to suggest that a rat is able to use its sense of smell to detect potential food items inside your residence while outside your home. In other words, smelling food items and even garbage inside your home can be a primary reason why a rat enters into the residence in the first instance.

A rat’s basic sense of smell also assists this rodent in ascertaining whether predators are in close proximity. The sense of smell activates a rat’s fight, fight, or hide response. Rats are not naturally prone to fight but are adept at shielding themselves from predators. Examples of predators that a rat’s sense of smell is likely to alert include cats, humans, and large birds.

When it comes to a rat’s sense of smell associated with day to day issues, survival, and atmospheric gyrations, the animal breaths initially through its nose with the intake flowing over a patch of skin containing smell receptors and what are known as olfactory neurons. It is here that odorants bind to small hair like projections. When that occurs a neural response is triggered, with information about the odorant conveyed to a rat’s brain.

Because a rat is born blind, it relies heavily on its sense of smell from the earliest moments of its life. During an infant rat’s initial days alive, its sense of smell really is its only way of navigating and understanding the world around it. This includes identifying the location of its mother in order to obtain nourishment from her.

Rat Sense of Smell and Environmental Conditions

Animals in the wild are vulnerable to changes in weather conditions. Those animals that are better able to “forecast” coming changes in weather conditions have a better chance of survival. Part of being able to “forecast” weather conditions is being able to detect and understand on some level alterations in atmospheric conditions.

Researchers have come to understand that through their sense of smell rats appear to be able to detect atmospheric changes in a manner that provides them guidance about upcoming weather conditions.

By way of example, if a downward change in temperature and an associated snowstorm might be in the offing, if a rat were unable to understand this forthcoming change in the climatic scene, the animal would be very likely to perish. Due to the structure of a rat’s nose and olfactory (smell) system, this rodent is able to detect even slight atmospheric changes. Detecting these changes aid a rat in understanding whether it is safe to go about foraging or needs to seek shelter.   

Rat Sense of Smell and Reproduction

There exists a second smell organ contained in a rat’s olfactory system known as the vomeronasal organ, or VNO. The VNO is located in the lower portion of a rat’s nasal passage, directly beside the septum.

When a rat sniffs, or takes a taste of something, dissolved molecules make their way to the VNO. The VNO permits rats within a particular species to detect pheromones released by other rats of that species. Through this process, a male rat is able to determine if a female is in heat. It triggers a response in a male to attempt to breed with the female.

All types of rats have this same essential multifaceted sense of smell. Indeed, other rodents, including mice, have a similar structure when it comes to their sense of smell and olfactory systems.