I have been looking for a chance to photograph a bee actually producing wax, on the left you can see the one bee that is "belly up" giving you a chance to see two wax flakes being produced under scales on its abdomen. Wax makers probably hang out near the honey stores because I often see them at this kind of feeder. I built some feeders for placement on top of a hive stack.
A short box is divided in half by two boards spaced 1/4" apart the two halves are sealed with wax, this allows the bees to crawl up between those two boards and down into the two reservoirs, I placed a screen set off of where I want the bees to travel by 1/4" this prevents nearly all bee drowning problems since they can't be anywhere without touching a walking surface.