Bodily needs such as hunger, thirst and sex create state of tension or arousal called a drive.

It is a general term covering wishes, needs, drives and interests that induce an organism to act towards a purpose.

Refer to non-biological elements that appeal to an individual even if he does not feel any need and trigger him for an action accordingly.

Stereotype behavior patterns of a whole species.

Refers to a biological balance displaying an internal stable condition regarding how and how much food will be taken by the organism.