I bought 12 pullets from Tractor Supply back on 4/10/10 and they were 4 days old at the time of purchase. The guy at the store told me that pullets are verified hens and that the straight run chicks were probably 50/50 hens/roosters. I went with the pullets because I didn't want any roosters. Starting about a week ago, one of my chickens has been making more noise lately in the morning and it seems to be crowing. I have the chickens in a 4x8 coop on wheels that I built in my garage for right now until I finish the outside run and coop. It usually crows in the morning before I open the garage door but then stops after that. After I open the door in the mornings, I feed them if necessary and change their water. Could this be why it crows in the morning? The crowing is also about 1.5hrs after sunrise so that is why I'm stumped as to whether it's a rooster or not. This particular chicken has always looked more developed and older than the others ever since it started getting feathers and now it is acting a little more aggressive than before. At what age should you know whether or not it is a rooster? I would think it would be clearly apparent by now but this is my first time having chickens so I'm still learning. Any help is appreciated. Thanks.