Coco Huts are often used in conjunction with a Petri Dish to provide a covered area for dart frogs to lay their eggs. They are about the same diameter as a petri dish so it's easy to do.
These are made from natural coconuts, so size, shape and color will vary.
These are coco hut seconds - these have minor imperfections like a crack or a piece broken off. They still function fine as a breeding spot for frogs or other animals but are not perfect huts. But this is also why they are $1 and not $5 :)