Leaving imprinted indoor ducks alone?

[Raenh]

My girls still come in at night, eat treats, drink and cuddle with me then into the indoor coop to sleep latch on door to keep cats out and the girls in - and out in the morning to the smallest backyard in duck history, and they hate being outside... they would rather turn right around and come back inside with me. I'd let them if I didnt have my insanely jelly pit to worry about.

Their poo is water soluble if you clean it up right away, and it's easy to clean up. I mop every day, it was WAY hard having 9 ducks living this way, but 2-3 is manageable as completely indoors.
I could do 6 with my current set up, but not be able to keep up with the clean up as completely indoor - so they'd have to be indoor at night/outside days.

Oh and all of my girls <not the 3 quackers, I had> but my 6 girls they saw the house as the big coop, so they would wait at the door at my moms to come in, or here the current 3 wait at the gate when it gets dark, waiting for me to open it, and they go right inside to their room.

 

[Duckie doodle]

I currently have 2 house ducks. 1 is a duckling and I have him/her inside a pond mold with a hardware cloth on top. The duckling is all alone. Unfortunately his other siblings didn't make it for hatch. The other duck is a 6 month old jumbo pekin drake whom is also extremely attatched to me, who stays in a dog crate but he also goes outside during day with his duck friends. What I suggest is what @Miss Lydia says. Get a mirror and a stuffed animal for them.