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Animal senses

A cat has highly sensitive eyes and ears.A cat has highly sensitive eyes and ears. Animals have senses to detect what is going on around them. We have the same five main senses as many animals: sight, hearing, smell, taste and touch. Our main sense is sight. Compared to many animals, our eyes see in detail and in a wide range of colours. However, some animals have more highly developed senses than we do, such as hearing and smell. A dog, for example, can detect sounds far higher in pitch than we can, and hear sounds much further away. Its sense of smell is hundreds of thousands—possibly millions—times more sensitive than a human's. Some other animals can detect what we cannot, like pulses of electricity.

The eyes of a slug in close-upThe eyes of a slug in close-up

Eyes and ears

The eye contains specialized nerve endings that detect patterns of light and send information about them to the brain. Other senses work in a similar way. In the ear, the eardrum is a thin piece of skin that vibrates when sounds hit it. Again, nerve endings detect these vibrations.

A cat's eyeA cat's eye
Mammals, birds, lizards and frogs have eyes and ears on the head. However, some animals have them in other places on the body. Snails and slugs have eyes on flexible stalks. A clam has a row of small, simple eyes in the fleshy frill or mantle along the gaping edge of its shell. A grasshopper has eardrums on its knees.

Some animals are nocturnal or active at night. They include cats, mice, bats, owls and moths. Their large eyes pick up as much of the faint light as possible. Animals that live in total darkness, like moles and cave salamanders or fish at the bottom of the sea, have tiny eyes or none at all.

Sharks have a highly developed sense of smell. Some species are able to detect one part per million of blood in seawater.

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