Hi. I'm a newbie at having chickens. I have 3 isa brown chickens - had them since they were born and they are now about 4 months old. I'm confused as to what sex they are. All their combs and wattles appear to be the same, the only difference I can pick is that 2 are bigger and have yellowish legs, the other is smaller and has greyish legs. Any help would really be appreciated please.