I am moving to a home with a pond and have heard that ducks and geese are good at keeping the snakes at bay. I would like to get about 6 (3 ducks and 3 geese) of different breeds and I need to know if i should get just female sexes? Would it be ok to keep them all together? The breeds are Ducks: Jumbo Pekin, Cayuga, and Rouen, and Geese: Toulouse, American Buff, and Embden. What do ya'll think of that?