People have been divining by the movement and actions of cats for centuries. This is known as Ailuromancy. Traditionally there is a connection between a cat and the moon. Many pagan goddesses were similarly linked to the moon.
The Scandinavian Freya—associated both with the moon and with fertility—rode in a chariot pulled by cats. The Roman Diana was able to take the form of a cat. Bast was the sacred cat headed goddess of Ancient Egypt. The cat is considered the bearer of souls of the dead in parts of the East, and in some places it is thought that, at death, a human soul will pass into the body of a cat.
Both white cats and black cats are considered lucky, dependent upon their actions. It is considered lucky simply to see a white cat, except in some parts of Britain where the reverse is true. A black cat needs to be either sitting to the right of the observer or moving from left to right to indicate good luck to come. If it moves from right to left, it is portending bad luck to come. Part of the fear of black cats comes from the Middle Ages belief that witches could turn themselves into cats (Diana, mentioned above, was regarded as a witch goddess).
There was also the belief that the cat was a familiar of the devil and a servant to the witch.
A black cat should be stroked gently along its spine to bring out the good luck and brush away the bad. To carry a stray cat into the house is to bring bad luck in with it. If a cat sits and washes itself, licking “against the grain,” it is a sign of a coming shower.
In many areas, if the cat carries its young to higher ground it indicates that a flood or severe cloudburst is imminent. If the cat sits with its back to the fire it means frost is on the way.
A sneezing cat near a bride can indicate a happy marriage to come. But under other circumstances the cat's sneeze means a storm is coming. In New England it is said that if a cat stares out of the window for a long time, it is a sign that it is looking for rain. On the coast of that area it is believed that a cat's pupils will he nearly closed at low tide but will dilate at high tide.
From the Greek ailouros, meaning 'cat'.
Since ancient times the mysterious cat has been associated with witches, the occult, and many superstitions, so it is not surprising that diviners used them to search for clues to the future. One of the oldest and most common method of ailuromancy uses the behavior of a cat to predict the weather. If it turns its tail to the fire, it foretells a change of weather, particularly rain or hard frost. If the cat lies curled up with its forehead touching the ground, it means that stormy weather is in its way.