the comb and wattles are more pronounced than they would be if it was a hen. look at the difference in the wattles on the 2nd one. she pretty much has none where the 1st ones are pretty big. that's how I tell the difference anyway. different people have different methods but looking at the wattles and comb work pretty good for me.Wow how can you tell he's a roo at that age I'm new so want to know how to do that