Now that the Silver Penciled Rock chicks are six weeks old, it's getting easy to tell them apart. Not only to the cockerels have much fiestier temperments than the young pullets, but their coloring is distinctive.
I've done a count, and I have five pullets (yay!) and seven cockerels (oh geez...) I think I've decided which cockerel gets to stay with the ladies; out of the seven, six have varying degrees of aggressive behaviors, including two which seem to delight in biting me when I go in. The seventh one is absolutely sweet, very gentle, stands off to the side and observes before going in for a nosh. I don't think he's ever bitten me, so that's a serious point in his favor. I have time yet to decide, but right now the odds are in his favor.