Eyes
A cat can see 6 times better than you at
night. But his nocturnal adapted eye is so
overpowered in sunlight that he has another eyelid under their outer lid to help
protect his eye during the day.
The nocturnal eye is bigger proportionally to its skull than
your diurnal eye is its skull. And the nocturnal pupil
opens much wider in low light . Both of these things let more light into the nocturnal
eye than a diurnal eye.
Nocturnal eye
Diurnal eye
The pupils of a
nocturnal eye are usually elliptic and can open much
bigger in proportion to a diurnal eye which usually has a round pupil.
Light passes through the pupil of all eyes, and focuses onto the retina by the lens. In the retina are more sensory nerve cells than anywhere else . They are light receptors called rods and cones. Rods are low light sensors and cones are bright light sensors. Most nocturnal eyes have few cones. Some have none at all. But, they have no shortage of rods. So, their night sight is good. You have fewer rods and more cones, so you have better daylight vision and see with more detail.
Eyeshine
Did you ever see an animal's eyes glowing at night
when light hits them? The nocturnal eye has a layer of tapetum lining the back of it. When light hits it,
the tapetum acts like a mirror so the light actually passes through the lens from the back
of the eye and shines through the pupil so we can see it.
Smell
This is another sense that a nocturnal animal is more sensitive to than
we diurnal animals are. A coyote's sense of smell is 100 times greater than ours. Nocturnal
animals use their sense of smell as a hunting tool.
Our
Human Reaction
"All of us are
born with a set of instinctive fears: of falling,
of the dark, of lobsters, of falling on lobsters in the dark..."- Dave
Barry
It is instinct to fear a predator's glowing eyes,
long, sharp claws and teeth, sounds, and sense of smell. They are his weapons.
The animal in us knows we can be prey. And we can't
see what's out there at night.
So, we feel fear.
What is fear?
Fear is a self-protection instinct. When animals (including humans) are in a situation they believe could hurt them, certain things happen. A burst of adrenaline makes the heart race fast. An overwhelming need to get away takes over. If the animal (like humans) has hair, the hair stands up (goosebumps), making the animal look bigger, and better able to protect itself.
Fear is the instinct that helps stop us from getting hurt or killed...which is good. But, sometimes, fear stops us from doing things that are fun or different because we don't know enough about them.
But, there are only a few
animals (nocturnal, diurnal, or crepuscular) that will attack humans.
Most will go out of their way to stay away from us. Because we are the
#1 predators. And it is their instinct to fear their predators.
Have you ever heard anyone say that they're a "morning person" or a "night person"? Some people like staying up later than other people. Does that make them nocturnal? No. It turns out there are physical differences between diurnal and nocturnal animals. But, if you have a cat (nocturnal), you know they will do things when the sun is up. And many people go out at night.
So, what's the difference between us? Why can't we (humans) get around at night as well as nocturnal animals? And why can't they do as well as we do in the day?
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