Contrary to what the adage may say, bats aren’t blind. Their eyes are indeed very small, and they may not be able to see quite as sharply as other night hunters, but it is still believed that their vision may surpass even that of humans.
In addition to this, whatever they lack in eyesight, they more than compensate for with an amazing skill called echolocation.
Bats are famous for their unique ability to “see” by emitting and receiving sound.
How do bats see?
Bats are nocturnal hunters, so their eyes are adapted to low-light conditions. Their retinas are full of photoreceptors known as rods, which enhance their night vision abilities. Together with this, they also possess a skill known as echolocation, which helps them navigate their environments using sound. Essentially, bats see with both their eyes and ears.
How Well Bats See with Their Eyes
Most bat species possess good vision. While their eyes function best in the low-light conditions present at dawn or dusk, it does not mean that they cannot see during the day or in the dead of night.
Like most creatures, they use their eyesight to watch for predators, navigate their flight paths, and detect and avoid crashing into things.
In low light, their vision might even be better than ours. The retinas of our eyes are made up of photoreceptor cells called cones and rods, which are responsible for sending messages to our brains about what we see in terms of color and light.
Bats’ retinas are loaded with rods which strengthen their night vision capabilities significantly. However, they cannot detect color as well as we do, but most species don’t really need to.
With over 1400 species of bats in the world today, there are variations in the strength of various species’ eyesight, but overall, their eyes function much the same as the eyes of other animals.
How Bats Use Echolocation to “See”
In tandem with their eyesight, echolocation is an incredible phenomenon used by bats to travel, hunt, and roost safely.
By producing ultrasound frequencies, bats bounce sound off objects around them and gather information based on the echoes that return to them.
When hunting, for example, a bat may emit what is known as a feeding buzz. This is the process whereby a bat locates an insect (or similar) and lets off a rapid series of calls to figure out its exact location before going in for the kill.
If the said insect is sitting on a leaf, the bat will use the leaf as a mirror to bounce sound against. It will then approach its prey from an angle, picking up echoes along the way to its dinner.
Many insects cannot hear these high-pitched frequencies and are therefore none the wiser to their fates.
Humans, too, cannot hear these sounds, but bats’ ears are tuned to recognize their own vocalizations distinctly, no matter the other noises around them. The calling patterns of each species of bat are distinct and unique too.
How Bats’ Eyes and Ears Work Together
Depending on the species, some bats rely more on their eyesight than echolocation and vice versa. Both navigation techniques have their benefits and different uses.
Some bats don’t echolocate at all, whereas others rely almost entirely on sound to hunt and fly.
For example, studies have shown that bats that mainly feed on pollen tend to use eyesight to locate flowers. Bats that eat insects, conversely, may prefer to sneak up on their prey using echolocation.
It has also been determined that the darker it gets at night, the higher the prevalence of bat calls becomes. This suggests that there may be a link between their night vision capabilities and their need to rely on echoes as it becomes increasingly dark.
Echolocation in some bat species also increases in bright light, likely because their vision is best in low light conditions like dusk and dawn.
Either way, what has been determined is that bats function best when they can use both their eyes and their ears to hunt and stay safe themselves.
The more information they can gather via these two sources, the more likely they will successfully search for food, travel, and avoid predators themselves.
Frequently Asked Questions about How Bats See
Why do bats fly in such wonky patterns?
When bats are on the hunt, their flying patterns may appear erratic as they are likely in the process of echolocation. The sound they bounce of various things and objects echoes back to them, providing them with information to approach identified prey at different angles in well-planned sneak attacks. When flying home to roost, they generally fly straight.
Do bats fly in the daytime?
Bats prefer to fly at night because their eyesight is better suited to low light, because food is more freely available, and because it’s easier to avoid predators. That being said, many bats and bat species do indeed fly during the day, depending on food availability and habitat.
Do lights repel bats?
As most bats are nocturnal, they will usually avoid bright lights where possible, particularly artificial lights.
Bats are intriguing and intricately designed mammals that have adapted into a rather special species. There is so much unique about them, from their eyes to their ears to their flying and roosting habits.
Today we know that the saying “blind as a bat” was based on the assumption that these sweet little vampires suffered from poor sight, when in fact, given the use of both their eyes and ears to “see,” they could probably fly circles around most other animals.