by Anupum Pant
While every teacher around the world is busy teaching their kids that bats are blind, the contrary is actually true. Bats aren’t really blind and they can see pretty darn well even in low light. In fact, their eyes work better than our eyes do in a dimly lit environment (eg. Moon light).
None of the bats’ 1100 species are completely blind. Although, there are a few which depend heavily on a technique called echolocation to navigate around objects which are near, they still have to use eyes to see objects which are far away. Additionally, most bats like to hunt in complete darkness (to avoid competition from other birds), so they use echolocation during such times [because eyes need at least some amount of light to be present]. The daylight hours spent by them to groom or sleep don’t demand much of their visual skills, but that doesn’t make them blind.
One way in which bat’s vision is poorer than our visual ability, is that they can’t see colors like we do. Everything they see is in black and white. This disability, if you may call it one, is compensated by their ability to detect light waves whose frequencies lie beyond the human visible spectrum. Flying foxes, however, which are actually bigger bats, can see colors.
So, simply put, bats can see, but they don’t have to use their eyes to hunt or move around. This makes your teacher wrong when he/she says chides you with the phrase – “Blind as a bat”
Bonus Bat Facts
- Bats don’t carry rabies. However, like humans, the disease affects some bats.
- Apart from vampire bats found in Mexico, Central America and South America, no other bats suck blood.
- Bats hunt insects above your head, they aren’t interested in your hair or your eyes.
- Bats can catch insects with their tail or wing membranes.
- Fruit bats are also known as flying foxes, they eat fruits.
- Bats collectively eat tonnes of insects and protect our crops.
- Some bats eat fish and frogs.
- Bats’ dung, is rich in nutrients. It is mined from caves, bagged, and used by farmers to fertilize their crops.
Echolocation: A bat echolocates by sending out streams of high-pitched sounds through its mouth or nose. These signals then bounce off nearby objects and send back echoes. By “reading” these echoes with its super-sensitive ears, the bat can determine the location, distance, size, texture and shape of an object in its environment. In some cases, a bat can even use echoes to tell insects that are edible apart from those that aren’t. – [Source]