I think I'd freak out if I saw a lump moving down their throat. lol
I didn't know ducks could eat mice. They're pretty big. That's helps me out a lot since it takes longer to cut watermelon & squash into small pieces.
I'm afraid I've spoiled my flock. When I cut myself piece of watermelon I leave bit more red on the rind than I would otherwise. I used to just throw it to them & let them eat it. It's kinda funny watching them try to tear piece off & flinging it couple feet away & then watching the flock race to get it first.
But I felt so bad that some didn't get much so I started holding the rind & giving each of them bites until it was all gone. Once it's too small to bite I tear the rind up for them. I do have to watch my fingers as them seem to want to bite where I hold it rather than the end they can easily bite piece off but they're learning. lol
Awww, poor drakes didn't get no lovin'. lol But I totally understand not wanting to get attached then having to get rid of them. I can't imagine which of my flock I'd get rid of if I had too.
The reason I have all male flock is my neighbor and I went in together to buy a bunch of Muscovy's. She already had some but was WAY lopsided on female to drake ratio. We was hoping a lot of them would be female, but nope, no such luck as it seemed most were male. So I said I take all males to help out & I really didn't want to deal with females anyway. I don't need eggs, I can get them from her.
Hoping it works out, if not my plan b is to rehome any that needs to go, to 1 or 2 different people looking for ducks or any kind of farm animal. One says he wants them as "pets" not to eat, not sure about other one. But I definitely don't want to rehome to someone that's going to eat one of my beloved pets.
Oh new trick, well not really a trick they're just smart.

My flock rarely comes into my front yard on their own, neighbor across street has dogs outside in fenced area sometimes & they'll starting barking scaring the ducks. But they ventured up there on day so I went out to walk around with them. As I walked around I kept stirring up crickets & the ducks would grab them. They learned to follow behind me waiting for me to stir them up. Boy they had a cricket feast that day! Now when I say to duckies to follow me to front yard & head that way, they do.
Sorry I got kinda long winded there. Can you tell I'm a new duck parent. lol