We are fairly new to raising backyard poultry. We started last summer when a neighbor gave us a few "extra" bantams. We had a couple of incidents, lost one to disease, a couple flew out and got lost to the dogs, then we had a massive midday raccoon massacre which brought our flock down to 3. Out of the original flock, the ones left are a Blue Cochin, a Silver Laced Wyandotte and a Rhode Island Red. My son is in the poutry project with our local 4H club and wanted to increase the size of our flock, so we decided we would try to raise chicks. After doing some research on the types of breeds, their temperments and their egg laying capabilities, we went to our local feed store and picked up 6 chicks - 3 Black Australorps and 3 Buff Orpingtons. My son and I went to a poultry breeders show recently and saw full-grown birds of the chicks we had picked & we had not realized how HUGE these chickens will be! The chicks are now about 3 1/2 weeks old, and they've grown tremendously, and we're wondering if it's too early to determine if there are any cockerels in our mix. We have one or two of the Buff Orpingtons which seem to be a little more aggressive, but that could also be that they are trying out their wings. None of the birds are going after one another. Then we have the Australorps, 2 are considerably larger than the 3rd. We know the 3rd could be a "runt", or its possible the 2 larger ones are cockerels. At any rate, we've tried to take photos the best we can. Any help would be appreciated. Also, if it's just too doggone early to tell, at what age should we begin to notice a difference? Thanks so much!