Step-by-step explanation:
He eats something.
Here, 
 The sentence is in simple present form so, it's yes/no question should also be in simple present form and he is a singular subject so, we should use does form of do verb for making yes/no question and while making yes/no question something changes into anything.
Now,
 Structure= Auxiliary verb + subject + v¹ + object + ?
Answer= Does he eat  anything?