sexing, i left a post further down is the poultry section as im having diffuculty with my 13 - though they are getting older now 5/6 weeks (i think - that un organised i didnt plot the day they turned up on the calender) their voices are starting to changed from the duckling 'peeps' into adult quacks, and i can deffinatly hear differences some sound like the ducks, and a few are making strange noises so im guessing they are the drakes.
You tube have videos on with people sexing them, i did find that quite usefull. depending on how accurtate my sexing is (hoping to get help) i would offer you a hand. im guessing your fairley local to me as you are a long the eden, im just outside cupar.