My 3 chickens have sand in their coop as a substrate. It is wonderful for them as easy to forage in, absorbs wet droppings, and keeps them cool in the summer. The big issue was picking up small poops. A cat litter scoop worked but not always. When I was at a stable they used something called a durafork. so i decided to make my own that was hand held and easy to maneuver in a coop. It could also be used for rabbit poop, bearded dragons or any other small animal on sand or similar substrate.
The author hasn't provided the model origin yet.