For easy cleaning, the Exo Terra Worm Dish consists of two parts. Mealworms must be retained when placed in a terrarium. Otherwise they will quickly "escape" and make their way through the substrate. They hide safely until metamorphosis is complete and they have become an inedible beetle.

Much sooner they will die and their decaying bodies will become a feast for harmful bacteria. The Exo Terra Worm Feeder prevents mealworms from escaping; however, they remain visible to the terrarium inhabitants.