Task: Sentence Ordering
Input (English): Steps: (1) An animal eats a lot of food to fatten up (2) The animal finds or builds a suitable place to hibernate where they can stay warm and protected (3) Their heart rate and breathing slow down to conserve energy (4) They emerge from the den when the weather is warming up again.  
Where does the following step fit into the given list of steps: The animal moves into their den 
Output (English):  After step 2.