At around 12 days old it is time to sex and pinion the ducklings. This can be a daunting task and if you’re not sure how to do this. It is best to do it with someone experienced or get someone to come help you the first time.
Sexing is done by opening up the cloacae and therefore it is also called vent sexing. Smaller bird species are being sexed using a microscopic probe. For the bigger birds like ducks, vent sexing works well as shown in the photos below.
The Vent Sexing Process
Hold the duckling on its back with its head pointing down your wrist in your right hand and its legs up in the air pointing away from you.
Expose the vent by holding the tail up with your left hand, and pressing in and up between the duck’s legs with the thumb and forefinger of your right hand. With very slow, gentle pressure, open the vent.
Observe the genitalia through the opening. Female ducklings have a cone-shaped organ that is more easily observable. Males have a smaller, longer, pointed organ inside a larger cloaca. The male’s organ may not even appear for several seconds after the vent is opened.