Is an organism's response to changes in it's environment.
Behaviour can be inherited or learned.
Both genes and the environment influence your behaviour.
For example, if a child is born deaf they don't hear people speaking so they don't learn to speak for a long period.
Some behaviour is inherited
Inherited behaviour is known as instinctive.
Animals will respond in the right way to a stimulus even if they have never done it before.
For example, new born mammals will suckle from their mothers without learning to.
Protect you from dangerous stimuli.
They are automatic actions.
Earthworms show negative phototaxis- move away from light.
Sea anemones wave their tentacles when stimulated by the prey's chemical.