We've been using Wyze cameras. They're not the best but they work fine and are cheap. Last year we used an indoor camera inside the coop about 100 feet from the router it worked good. The only issue is it needed to be plugged into power and kept dry. This year we got an outside version that uses...
I haven't seen any ducks checking out the boxes. My hen Ring teal looks at them from the pool but never goes up to any. I think the Hoodeds are using one at night because the past 2 nights I've had a camera out and see them fly back to the pool at 5:30 am. I don't know where they are flying from...