Showing posts with label Lion. Show all posts
Showing posts with label Lion. Show all posts

Why do Cats Purr?

            When a cat wants to express satisfaction or pleasure, it purrs. Purring of a contented cat results in a low vibrating noise. It is a kind of low continuous rattling hum and has nothing to do with a cat’s real voice. A mother cat purrs when it wants to call her kittens for feeding. At birth, the kitten’s stages after birth, it is the purring of their mother that helps them to keep contact. Once the kittens start feeding themselves, the mother stops purring. So, we can conclude that purring began as a kind of homing device.

A Cat and Kitten

            Now the question arises- how does a cat produce the purr?

            The vibrations in a cat’s vocal cords cause the purring sound. When a cat takes air into its lungs, the air passes through the voice box that contains the vocal cords. If the cat then wants to express its satisfaction, it will allow the vocal cords to vibrate as the air passes in and out of the lungs while breathing. When it chooses not to purr, the air does not affect the vocal cords and thus does to produce any sound.

            Although there are many members of the cat family such as lion, tiger, leopard, jaguar, ocelot and lynx, whose throat structure is quite different from that of a cat and hence they cannot purr. However, they can make kinds of sounds.

Why do the Eyes of Some Animals Shine in the Dark?

            Have you ever seen a cat sitting in the dark? Though its body may not be visible, its yellow eyes shine in the darkness. The eyes of many other animals like tiger, leopard, and lion also shine in the night, just like the eyes of a cat.

Eyes of cats, tigers, lions, leopards, etc.,shine in the night

            The eyes of these animals have a thin layer of a special crystalline substance, which reflects the light falling on it. This reflected light is the cause of the shine. In the night, even the smallest amount of light falling on this crystalline surface gets reflected and thus eyes who can see things clearly in darkness are called nocturnal animal.

            Studies made on cats have shown that behind the retina of eyes, there is a crystalline layer called the luminous tape turn, which reflects light. Due to this layer, a cat can see clearly in dim light ad its eyes shine in the dark when light is directed on them. Many animals do not have this crystalline layer; hence their eyes do not shine in the dark.

            It has been observed that the color of the shine varies in different animals. It depends upon the number of blood vessels present in their eyes. If the number of blood vessels is large, the color of the sine is red and if the number of blood vessels is less, the color of the shine is white or pale yellow.

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