Why drains get clogged?

Drains get clogged when wastes and residues from food, oil and fat blocks the flow of liquids going through the drain pipe. Other drain pipes in the bathroom, get clogged because of soap, soap oil residues, shampoos and hair. It is best to be more careful of what you drain and do a regular treatment by pouring some drain cleaners from time to time so that it clears any clogged residues.