Can you identify the rooster?

[ChickenKid11]

My chicks are 3 weeks old. And I was wondering if you could tell which ones are the roosters? If you can how?

 

[Fred's Hens]

Cockerels are easier to spot at 6 weeks. In most single comb breeds and even the single comb hybrids, it is the cockerels that normally sprout red combs and red wattles at that age. Pullets generally do not show much red in the comb and little to no redness in the wattles at that age. It's best to wait a few more weeks. At 3 weeks, it is far too easy to just guess without much factual benefit.