Rats are one of the few nocturnal pets. They are social during the day as well, but they’re very active during the night time, and you might find them exercising on their wheel or playing with toys at night. If they can do all of this stuff at night, they must have good night-vision, right?
So, can pet rats see in the dark? Surprisingly, pet rats can’t see well in the dark. To compensate for their extremely poor night-vision, rats use the whiskers on their face to navigate in the dark. Their whiskers help them sense nearby objects and lead them to their desired place.
The rest of this article will discuss some essential topics related to the rat’s ability to navigate at night, including how their whiskers work, how good their vision is, and what other senses they use to get around when it’s dark out. To learn more, read on.
How do their whiskers work?
Rats have whiskers like we, humans, have fingers.
Our fingertips help us detect the objects and obstacles in front of us. They help us feel what the object is and warn our brain to stop moving so that we don’t collide with the obstacle. When we can’t see, we put our hands in front of us and feel the space. If the object is small, we remove it, or we change the direction we’re going in. This is exactly the case in rats, but their facial whiskers perform the task for them.
Furthermore, as pet rats are very intelligent animals, they use their facial whiskers differently depending upon the environment they’re in (much like how we use our hands). If the environment is unfamiliar to them, they move slowly and steadily, detecting every nearby object and pushing it to create a path for them if necessary. If they’re in a familiar environment, they use their whiskers less as they don’t need to detect every object. They also move faster and swifter.
A study conducted by Sheffield University explored how the direction of a rat’s whiskers changes depending upon the surroundings. Rats experience all of their surroundings using their whiskers when they aren’t used to the place. Their whiskers are broadly arranged, and they feel the floor and walls of the cage in addition to the obstacles in front of them. If their surroundings are familiar and no big changes are made, their whiskers point straight in front of them to feel the obstacles only, so that they don’t collide when moving at a higher speed.
What does a rat’s vision look like?
Besides being nearly blind during the night, their vision differs from ours during the daytime as well. In fact, the similarities end at rats not being totally colorblind. Everything else about their vision is more or less different.
Firstly, the retina of a perfectly healthy human eye has three color-sensitive cones, which are blue, green, and red. As we all know, light travels like waves. The colors we perceive are basically the wavelengths our eye responds to. This range is usually 380-740 nm and includes color shades starting from white-purplish-blue and ending in a dark red. We can’t see anything beyond this visible range. Before this range is the ultraviolet range and after this range is the infrared range.
Rats have just two color-sensitive cones. Those are blue and green. A rat’s vision ends at around 560nm, which is a green-yellow tone, with the green part being much stronger. So rats can not see any shade of red & orange along with bright yellow. However, the blue cones of rats are shifted a little bit towards the ultraviolet range, and so, they can see some shades of blue normal human beings can’t see. The color would be some sort of a blue-white shade.
In short, the colors we see are purples, blues, greens, yellows, oranges, reds, and every other tone in between. The colors rats see are whitish-blues, purples, darker blues, and greens.
Secondly, rats have trouble distinguishing the limited colors they can see. Due to this, they see some blue-green colors like white and others as grey. Their retinas also have more rods that can sense light and dark than they have colored cones, so the images they see are much more unsaturated than the ones we can see. Rats can distinguish colors if they’re taught to, but they focus more on brightness, which is one more reason why rats have very poor night vision.
Lastly, the vision of a rat is very blurry. As rats don’t have many cone cells to give them a sharp vision, they see very smooth pictures. Rats only see clearly when they’re a few feet away, unlike us, who can see many feet away. More than a couple of feet away, rats only see movement or very large shapes (how a person with short-sightedness would see).
To summarize everything, the vision of a rat sees limited colors (ultraviolet, purple, blue, green), fails to efficiently distinguish between colors, relies on bright and dark signals to see, is pretty unsaturated, and is blurry. Rats also perceive depth badly.
Albino rats are a whole other case when it comes to rat vision. Their irises are unpigmented, and they can’t block light, as well as other rats, would. This leads to retinal degeneration soon if they’re kept in a luminous environment. The vision of albino rats in normal light is dazzling, flooded with patches of light and dark that are hard to define and is also very blurry.
Are rats really nocturnal if they’re night-blind?
It’s not necessary for an animal to have a great night vision if they’re nocturnal. Yes, animals like owls have extraordinary eyesight during the night time, but so do cats, who are neither diurnal or nocturnal.
In fact, many primarily nocturnal animals besides the rat have poor eyesight. The list includes badgers, bats, black rhinos, capybaras, and hedgehogs, amongst many others.
All of these animals have some sort of sense they rely on to perform their nocturnal activities, such as good hearing, good sense of smell, good sense of touch, etc.
What really defines whether an animal is nocturnal or not is it’s sleep schedule and activity, and pet rats tend to stay awake at night.
Rats have an incredible sense of smell. When they’re born, rats are totally blind and rely on their sense of smell for locating their mother for feeding. As they grow up and this sense develops further, they use it very wisely.
If you leave food for them in a corner of the cage, they can locate it immediately. Rats can smell meters away. Pet rats use this sense to find their rodent friends at night as well.
Being rodents, rats have a great sense of hearing, which is much greater than ours. For a measure, we stop hearing frequencies above 20,000 hertz. Rats can hear frequencies up to 80-90,000 hertz!
This means they can hear many sounds we can’t, like the echolocation of a bat or a communication signal of a dolphin. To rats, even the sound of a crinkling wrapper is distressing and loud. Pet rats can use this excellent sense of hearing to navigate at night, as a substitute for their poor vision.
Even though rats are nocturnal animals, they have pretty poor eyesight in the dark. To compensate for this, they use their whiskers, sense of smell, and sense of hearing to help them navigate during the night time.