Although many newborn animals enter the world well able to defend for themselves; others rely heavily on one or both of their parents for survival. This creates a need for communication between the generations.
Parents can exchange information with their infants even before they are born or hatched. The child will signal its needs and in turn responds to important messages from its parents.
The parent-child relationships in the animal kingdom that evolve from this information exchange involve many different aspects. These include feeding, and protection; helpless baby animals will need to heed the warnings from their parents. Young animals may also look to their parents for comfort and warmth, and to keep them clean.
There is further need for communication when it comes to wandering children. In these situations, parents will have to fetch and carry their straying offspring home again. An infant lost or otherwise in distress usually has special means of letting its parents know it is in trouble.
The methods of communication young animals learn in the period of their upbringing are essential for later life. If things go wrong at an early age, it could compromise their ability to learn the language that they will need as an adult.