Quote from : Puella Magi Madoka Magica, Vol. 03 Book

Kyubey: You have no idea how much difficulty we go through trying to understand your human values. Presently there are six billion, eight hundred million of you, and you're increasing in number by a hundred every four minutes! What's the huge fuss over the death of each and every single creature? Madoka: If that's how you think of us, then yes, I see you are our enemy.