Posts tagged ‘Total Darkness’

How do bats fly in the dark?


A bat can fly in total darkness and yet never bump into anything.  The bat has a built-in radar system.  As it flies through the dark, it utters a twittering sound that is too high-pitched for us to hear.  Echoes of these sounds bounce back from any nearby object.

But listening to these echoes with its big ears, the bat is able to avoid obstacles in its path.  The bat also uses echoes to locate the mosquitoes and other insects if catches and eats.  It isn’t true that bats are blind.  They do depend mainly on their keen ears, but most bats can see in daylight. – Dick Rogers

How can a cat see in the dark?

Cats can see better in dim light than we can because the pupils of their eyes can open much wider and receive more light than our eyes can.

You may have heard that cats can see in the dark because they have special kinds of eyes.

It is true that cats can see much better than we do in dim light.  But cats cannot really see in total darkness.


In bright sunlight, the pupils of cat ’s eyes become narrow slits that shut out much of the glare.  At night, they widen to great circles, almost as large as the entire eye to let all the light there is.

Inside a cat’s eye is a special mirror like material that helps make the eye extra-sensitive to light by collecting the dim rays of light and reflecting them back to the retina, where the act of seeing begins.

When you see a cat’s  eyes glowing beside the road at night, it is because the mirror like material is reflecting the light from your flashlight or the headlights of a car.

Many animals active at night such as deer and owls, are able to see well in dim light for the same reasons cats can.   – Dick Rogers


Why do cat’s eyes glow in the dark?


Most of us have seen a cat’s eyes shining at us in the dark as we drive by.  The cat’s eyes themselves do not glow.  The glow is only a reflection of the cat’s headlights.

A cat has an extra mirror like material in the back part of its eyes.  This special material reflects direct light and causes the cat’s eyes to “glow”  brightly.

A cat’s eyes have slit like pupils.  In bright light the pupils become narrow slits that shut out much of the glare.

At night they widen to great circles to let in all the light there is.  But even a cat cannot see in total darkness, as some people think.

Many animals active at night, such as deer and raccoons, have this mirror like material in their eyes, too. – Dick Rogers