How old are they ? My Muscovy have always been next spring for mating and laying so I am not sure when your boys maybe ready. here it’s always been the hatch one year breed and lay the next spring plus that must be determined by where you live to because I have a friend in Texas who has breeding and eggs and hatched all yr. so climate must make a difference mine lay usually March thru September then are done till next season. And all they need in winter is a way to get out of the weather if they chose and protection from predators plus feed.