How or when to tell Ducks gender?

[LilDucky85]

How or when can I find out the ducks gender? They are 7, 6, and 5 days old today. They are Pekins, one Crested Pekin, and one fawn and white Runner-Pekin mix.

 

[KellyHM]

One way is to vent sex them, although it's kind of difficult...you can Google how to do it. Some people say the drakes have a quieter raspy quack even when they're little. The sure fire way is to wait until they're 3-4 months old and the boys grow their drake feathers.