I did a lot of research when i first got quails. males can be kept together under very specific circumstances: they have to be the same brood to be housed safely together. otherwise, they apparently hurt or even kill each other. I bred some quails but the other cage broke. i put the young ones with their parents and they mostly left each other alone. At first the adult females picked on the young male but soon ignored him and his sister. females can be kept together. also, males mate almost constantly and need to have at least two females with him so he isnt focusing directly on one female (males pull head feathers)