HI Guys! I have a pair of mallard ducks which are free ranging ? i am giving them wheat corn and all the table scrap they have plenty of water throughout the day but I dont have any kind of pond like thing for them to bath. they seems to be very healthy active but for the last like 6 to 7 months my duck hasn't laid a single egg ? i have tried calcium suppliments also but it didnt made any difference ? Tell me what to do ..?