I've heard that Silkies are harder to sex than most chicks. I bought seven Silkies and a Showgirl. They are about 10 weeks old now and so far they all look like hens. I have another Silkie chick that is about a month old and I can already tell he is a rooster. The comb is reddish and growing. Should I be able to tell by now if any of the first batch is a rooster?