Are Domino Roaches safe for Crested Geckos to eat? I know this is a frog forum, but I know the reliable sources on this forum. Also, if it works out it will go in with frogs. Anyways, I took interest in having a bio-active substrate for all the benefits and also it adds a little bit of activity to the vivarium when my geckos sleep. I assume that the geckos will eat at least some of the roaches, probably not many because they usually eat CGD and don't take much interest in hunting. There's a substrate of a homemade ABG type mix (Including top soil) capped with a thin layer of coco fiber and mulch then a layer of leaf litter.