From the animal kingdom the spiders are the popular ones of the arachnid family, they have thousands of shapes and sizes.
The body of the spiders is divided into two fragments, they have a tiny brain, they have eight legs, and most have eight eyes, others have six eyes and others that may not have eyes.
The curious thing is that their eyes are composed of ocelli, formed with a cornea and a photoreceptor layer, they have a retina composed of four light-sensitive layers; one layer focuses on an object, the others appear out of focus, and that causes the final image to be blurred. In spite of this, the eyes serve as transmitters to the brain so that they can find their prey.
Its particular characteristic of the eyes makes it have a very sophisticated vision that makes it an infallible hunter and can calculate their prey remotely easily.
In the case of tarantulas, they have photoreceptors in their eyes that allow them to use the polarized light of the sky to determine where they can locate their nest.
In the case of weaving spiders they are blind, but they are handled by touch and smell.
Another thing that is known is that they all possess poison, although what varies is its intensity, that is, it can be felt as an ant bite or major consequences for health and even life.