Gender Help Please?

[Kendal]

A little while back I bought several straight run chicks from various places, one was Tractor Supply, and now I'm concerned I've ended up with a whole lot of roosters! I thought the main way to tell was by the comb, but when I googled it I read that a lot of hens have large combs too and that's not always the best way to tell? Any help would be greatly appreciated! I also have one little black chick that I'm not sure the breed of, my mom picked it out from Tractor Supply for me and doesn't remember what breed it was. Thank you!
Small black mystery chick, 5-6 weeks


RIR, about 3 - 3 1/2 months


Silkie, about 10-11 weeks

Australorp, 6-7 weeks

 

[AlleysChicks]

All are cockerels.

The first chick may be a Asian black.

 

[AnimalGeek23]

All of them are cocks. You might have some problems dealing with fighting if they are in the same flock.
Oh, and btw,

 

[Kendal]

All of them are cocks. You might have some problems dealing with fighting if they are in the same flock.
Oh, and btw,

Thank you! I'm sure I'll have plenty more questions and well crap, that's what I was worried about! I had my suspicions, but I was really hoping the little black and the Silkie were hens.

 

[Brahma Chicken5000]

I would wait and see with the Rhode Island Red. At 12-14 weeks of age it’s normal for pullets to have a comb & wattles close to that size depending on breed.