what kind of chicks are these?

[Logan Martin]

There wings are white. And how can you tell which ones are hens or roosters?

 

[Hedera]

It would help if you posted pictures and how old they are. Depending on the age and breed, you can usually tell the sex by the size and redness of the comb and wattles (bigger, redder comb and wattles on rooster). Some breeds you can feather sex as well