Question

The grass eating animals chewing continuously even when they are not eating?

Answer 1

the grass eating animals chewing continuously even when they are not eating are called herbivorous animals

Answer 2

A grass eating animal like cow use to move its mouth even when they are not eating because, at that time they were eating the store food.

And such process is called rumination , and animals which do so are called ruminants.

They do so to beacuse to digest the food which they had not eaten at the beginning.