We just purchased two ducks and are trying to determine if they are male or female. We have one female pekin already who is 3 months old but definitely has the loud, distinctive quack. The 2 we purchased are supposed to be 6 months old and one is a Pekin and one is a Khaki Campbell Runner mix. We cannot get the ducks to make any distinct noises other than a very quiet, almost constant noise. They were orginially penned with hens and roosters in poor conditions. We have only had them for two days but they do have access to a creek and yard with us. The Khaki Runner mix is very aggressive with our original younger Pekin so we separated it. We need help identifying if the two new ducks are male or female so we know next steps for these ducks. We are new to raising ducks. Thanks!