I have 3 Mallard hens but they weren't broody when a friend asked for some Mallard babies. Back in late Feb. one of my Mallard Hens sat on a nest of eggs, then by the end of the third week she was having a hissy fit, I crawled into the duck house to check the nest and it looked like dang mice had eaten all of her eggs, just a bunch of broken shell left in the bottom under the nest. We wrapped the bottom of the house in hardware cloth to prevent it happening again. All 3 Mallards were laying again and had 16 in the nest, My Buff Orpington chicken had just gone broody so I stuck 11 of them under her. The next day my Maran Hen went broody so I stuck four under her. As of a week ago my youngest Pekin and my Magpie/Runner cross both went broody so they're on ducks eggs too LOL I noticed tonight one of my Mallard Hens is starting to act broody and she's been sneaking under my Clematis bench in the daytime...I'm going to check in the morning to see if she's sneaking in there and laying eggs.
Update: one of the eggs under my BO Hen hatched in the night, I added the two babies that I hatched in here last night under her, she accepted them beautifully...I just checked on her and one of her eggs has barely any shell on it, solid pure white membrane so I brought that one in, stuck it in the bator along with a warm wet paper towel. So looks like I'll have another baby to tuck under her tomorrow morning LOL I'm heading out right now to stick the two babies that hatched day before yesterday under her.
Michelle