Can roosters tell the sex of a chick? Back in August we bought 3 Easter-Egger day old pullets. Oliver and Leo our 2 roosters always ignored two of the chicks, but at any chance they would try to kill the third chick (Penny), that turned out to be a rooster. They would even try to peck Penny from the other side of the chicken wire. Anyone else had any experiences like this? Can hens and roosters sex day old chicks?