I have 1- 3 month old sebright and 9- 2 month old mixed bantams. These were straight run and I got them from a woman who lives a few hours north of me. NOBODY is crowing yet. Is it really possible that all of them are female? I mean I know its possible but is there anything else I should be looking for at this age to tell if they are male? I have 4 full size chickens and don't know if bantams mature more slowly etc. Thanks.