In Major's speech, he divides the world into friends and enemies. how does he define each group?

From the text:

"I have little more to say. I merely repeat, remember always your duty of enmity towards Man and all his ways. Whatever goes upon two legs is an enemy. Whatever goes upon four legs, or has wings, is a friend. And remember also that in fighting against Man, we must not come to resemble him. Even when you have conquered him, do not adopt his vices. No animal must ever live in a house, or sleep in a bed, or wear clothes, or drink alcohol, or smoke tobacco, or touch money, or engage in trade. All the habits of Man are evil. And, above all, no animal must ever tyrannise over his own kind. Weak or strong, clever or simple, we are all brothers. No animal must ever kill any other animal. All animals are equal."