Bats and Echolocation
The phrase ‘blind as a bat’ has always been one that’s been firmly within the lexicon of the general public. However, this phrase is actually much less accurate than one might think. While a bat doesn’t necessarily have the best conventional eyesight, these creatures have a little something in their locker that more than makes up for their shortcomings in that department. This is, of course, is echolocation.
What is Echolocation?
Echolocation is a phenomenon that can be found across the animal kingdom in whales, dolphins, some birds, and indeed, bats. This involves these creatures using high-frequency sound waves to perceive their surroundings. This sound they make allows them to sense other animals around them, hunt their prey, and scout out their environment. So, for bats, this ability is their own unique form of sight through sound.
Bats can use this skill to keep in tight packs with their group, constantly making noise to alert other bats of their whereabouts and also sense those around them.
Plus, this skill is invaluable for bats when flying around and traveling through the night sky. This skill allows them to avoid colliding with the environment around them and is so precise that bats can even sense if they can fit through gaps that are merely 3/8 of an inch wide.
How Does Echolocation Work?
Echolocation is the act of using high-frequency sound waves to create echoes. These echoes ricochet off the objects in proximity and are then heard by the bat thanks to their supersonic hearing capabilities. This means that they can then pinpoint exactly where an object or life form is and then act accordingly. Bats make this high-pitched noise through their mouth and nose and with this noise, they can locate objects as insignificant as a strand of human hair, for example, showing the potential of the bat’s hunting capabilities.
Can Humans Hear Echolocation?
While in some very rare cases a human ear will be able to make out these sounds at the lower end of their frequency scale, in general, a human cannot hear echolocation take place. This frequency occurs at somewhere between 20 kilohertz and 200 kilohertz, so unless you are gifted with very well attuned ears, you’ll be unable to make out the communication methods of bats.
How Can Bats Hear These Frequencies?
The simple answer to this question is through the phenomenon of evolution as bats have adapted to this method over time. However, for a more scientific response, bats can hear these frequencies thanks to their ear and brain cells being especially attuned to the supersonic sounds. This is thanks to the mass of receptor cells in their ears making them very sensitive to sound and therefore, able to hear these ultra-high pitched tones.
The bats also have the ability to move bones in their ear and relax muscles to a certain degree that allows them in some cases to distinguish a tone to 0.0001 of a kilohertz. This whole process takes just six milliseconds in total and ensures that the bat doesn’t deafen itself when hearing these tones.
How Loud Is Echolocation?
Echolocation can be very loud indeed, ranging from 50 to 120 decibels. Which, to give you some scope is about as loud as a fire alarm held about 10cm away from your ear. This would normally be damaging to the human ear but thankfully, because the sound is delivered at such a high frequency, we can’t hear these potentially harsh sounds.