Polish ...any specific clues as to what to look for in telling the gender?

[LindsaySinai]

I've been pretty good about sexing my chicks early on but I'm stumped with the polish. Is there anything that I can look?

 

[love2grinchicke]

developing wattles, spikier crests.

 

[LindsaySinai]

They're still two young for that...only about 3.5 weeks. I'm just curious because two of them are developing their "top-hat" a lot faster than the other two. Does that mean anything?