Two questions: What breed of duck are they? And how high off the ground are the boxes? Sounds like because you have a ramp this could be the key. I have not seen ducks utilize the boxes if they have to jump/hop up to them
Discussion
2 khaki Campbell, crested, pekin. Boxes are about waist high with the ramp being pretty steep. I’ll have to put a camera out there. I hope they keep it up, easier to collect what’s and they’re a lot cleaner too.