Calling groups of ducks can be a challenge. Some can break off and leave, while a new group may join in. Combine the constant shuffling of flocks with multiple guys calling and a lot can go wrong in a hurry. Communication and observation are key when it comes to duck calling groups. Pick out birds that seem most interested and work on them, but keep yours eyes open to what other ducks are doing and your ears open to hear the calling and communication of others in your group to know if there might be more promising ducks that have shown up.