What is the Home of Infants? What transgression does Equality commit here?

From the text:

We remember the Home of the Infants where we lived till we were five years old, together with all the children of the City who had been born in the same year. The sleeping halls there were white and clean and bare of all things save one hundred beds. We were just like all our brothers then, save for the one transgression: we fought with our brothers. There are few offenses blacker than to fight with our brothers, at any age and for any cause whatsoever. The Council of the Home told us so, and of all the children of that year, we were locked in the cellar most often.