Sally, Ducks need a bit higher humidity during incubation than chicks (40-50%) and a bit more at lockdown as well (55-65%). Ducks need to be able to dunk their entire bills to clear their nasal passages so a bit deeper bowl than for chicks is required after the 1st couple of days. I have found that either a shallow pan they can step in & out of or a deeper bowl that they can't get their bodies into at all (tall & narrow) works best. I have seen people use chip dip containers with holes cut in the lids so they can get their heads but not their bodies in for younger ducklings & the taller cottage cheese containers after a week or 2 (depends on how fast baby grows). These will likely need to be fastened to the side of the cage with twist ties or Zip Strips. I move to shallow pans or gallon buckets after a couple weeks. I have also found that brooding ducks on wire is SOOOOO much less messy than brooding them on shavings. paper, etc. I use a wire bird cage for my ducklings for the 1st couple days & then move them to my wire stack cage by about a week old depending on breed & how fast they grow. Ducks make a LOT of mess & love to splash water everywhere. If they are on wire they can even be brooded WITH chicks without totally soaking them as the water will drain right out. Good luck with your duckies. They are adorable.