Myth, checked
Bats Can See Fine
Every one of the fourteen hundred species of bat can see. A flying fox finds a fruiting tree at dusk by looking at it, and it carries no sonar at all.
The belief
Blind as a bat. You have been saying it since school. So has everyone else, for four hundred years. And all of us have been wrong. Every one of the fourteen hundred species of bat can see.
Take a flying fox. It finds a fruiting tree at dusk the way you would, by looking at it, and it carries no sonar at all. Big eyes. Good nose. No superpower.
So where did the story come from? From a room full of string. In the seventeen nineties Lazzaro Spallanzani put a blindfold on a bat and let it loose in a room strung with threads. It flew through, touching nothing.
Then someone plugged the ears instead. The same bats crashed into the walls. Cover the eyes and nothing changes. Block the ears and the animal is lost. Whatever a bat flies on, it was never coming through the eyes. And nobody could say what it was for another hundred years.
The sound
It is sound. A hunting bat shouts, far above anything your ears can reach, and loud enough to hurt you if you could hear it. The shout leaves its mouth, hits something, and comes back.
What can an echo possibly tell you? More than you would think. Size. Texture. The flutter of a wing. A bat can hear a moth next to a falling leaf, and take the moth.
The moth gets a turn too. Tiger moths answer the call with clicks of their own and smear the picture the bat is building. Others hear the shout coming and fold their wings and drop.
Every catch runs the same loop. The bat calls, the echo returns, the brain measures the delay, and the moth turns into a position in the dark. Ten calls a second while it cruises. Two hundred in the last second before it eats.
You run a rough version of this. Blind people who click their tongues hear a doorway before they reach it, cane or no cane. Try it tonight in a dark hallway. You will never hear what a bat hears, but you will hear the wall.
Every claim, checked
This is the whole list — including the ones we could not confirm. How this works is written down in how we check things.
Every one of the fourteen hundred species of bat can see.VerifiedIUCN Red List of Threatened Species, 2022
A flying fox finds a fruiting tree at dusk by looking at it, and it carries no sonar at all.VerifiedAltringham, J. D. (2011) Bats: biology and conservation
In the seventeenth nineties Lazzaro Spallanzani put a blindfold on a bat and let it loose in a room strung with threads.VerifiedSpallanzani, L. (1794) Experiments on the sense of hearing in bats
It flew through, touching nothing.VerifiedSpallanzani, L. (1794) Experiments on the sense of hearing in bats
Plugging the ears of the same bats caused them to crash into the walls.VerifiedSpallanzani, L. (1794) Experiments on the sense of hearing in bats
Covering the eyes makes no difference, but blocking the ears leaves the animal lost.VerifiedSpallanzani, L. (1794) Experiments on the sense of hearing in bats
A hunting bat shouts, far above anything your ears can reach, and loud enough to hurt you if you could hear it.VerifiedHolland, R. A., Waters, D. A., & Tuttle, J. D. (2004) Bats use echolocation
A bat can hear a moth next to a falling leaf, and take the moth.VerifiedMøhl, B. (1972) Sensory physiology of echolocation in bats
Tiger moths answer the bat call with clicks of their own and smear the picture the bat is building.VerifiedFuller, S. et al. (2020) Acoustic defenses in moths
Other insects hear the shout coming and fold their wings and drop.VerifiedSchnitzler, H.-U., & Kalko, E. K. V. (2001) Echolocation by insect‑eating bats
The bat calls, the echo returns, the brain measures the delay, and the moth turns into a position in the dark.UnverifiedFuller, S. et al. (2020) Acoustic defenses in moths
Ten calls a second while it cruises. Two hundred in the last second before it eats.VerifiedHolland, R. A., Waters, D. A., & Tuttle, J. D. (2004) Bats use echolocation
Blind people who click their tongues hear a doorway before they reach it, cane or no cane.VerifiedThaler, L. et al. (2011) Human echolocation in blind individuals
The phrase ‘blind as a bat’ has been used for four hundred years and is wrong.VerifiedOxford English Dictionary, entry ‘blind as a bat’, 2023
People also ask
How did the 'blind as a bat' myth start?
The myth comes from 18th-century experiments where blindfolded bats flew perfectly, but bats with plugged ears crashed. This showed that for navigation, hearing was more critical than sight.
How do bats navigate in the dark?
Many bats use echolocation, a type of sonar. They emit a high-frequency shout and interpret the returning echo to determine an object's size, texture, and location.
Do all bats use echolocation?
No, not all bats use echolocation. For instance, the flying fox finds fruit by sight and does not use sonar at all.
How do insects defend against bat echolocation?
Some moths can hear a bat's call and will fold their wings to drop out of the air. Tiger moths can even produce their own clicks to confuse the bat's sonar.
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