You are presented with the quiz "what is used to make an animal realize that it needs to replenish from a natural drinkable source" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "thirst is used to make an animal realize that it needs to replenish its bodily water by the body" and "water Water in the area's natural water bodies is drinkable as such". 

So, what's the best answer to the question?


 

     thirst      