Duck Eggs Under Broody Hen

[JavelinaFarms]

Hey all, have been having a lot of broody hens and have hatched several successful clutches. We decided to try our hand at hatching ducklings and are having a lot of trouble.
On the 1st clutch of ducklings, only 1 hatched and it died about 24 hours later. We thought that maybe the duckling wasn't able to get enough water? The duckling was curled up under mama hen.
Clutch #2, 1 duckling hatched about a week early. None of the rest of the eggs hatched. We tried to keep the little tyke corralled in the box with mama to encourage her to stay on the eggs. She did, but none hatched.
Clutch #3 - the duckling didn't make it out of the egg fully and died. The other 3 eggs didn't hatch.
It looks like we are getting about 1 duckling per clutch, most of the chicks cant make it out of the shell. I have cracked open the eggs and they all die around hatching. The shells are a lot harder than my chickens were when they hatched. Only 1 duckling still alive out of 3 clutches.
What am I doing wrong?

 

[oldhenlikesdogs]

When ducks brood their eggs they come back wet to the nest on purpose when they take their daily break. A chicken doesn't provide enough moisture to hatch duck eggs, I think. So that may be why you are having troubles.

 

[JavelinaFarms]

When ducks brood their eggs they come back wet to the nest on purpose when they take their daily break. A chicken doesn't provide enough moisture to hatch duck eggs, I think. So that may be why you are having troubles.

So do you think I should take a spray bottle out there and spray the eggs once a day?

 

[oldhenlikesdogs]

I haven't experimented with hatching duck eggs under anything but a duck. Hopefully someone else has and will give you some better advice.