You are presented with the quiz "What do animals do when the available nutrients in an environment decrease?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "if the amount of available food and water decreases in an environment then animals may leave that environment to find food and water" and "food and water provided to patients by mouth is the usual means of providing nutrition to patients". 

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


 

   they leave to find them        