Dubia are not a very active species of roach and they tend to burry themselves in substrate. When feeding them to an arboreal species like tokay, I have found the best thing to do is place the dubia in plastic "gladware" type bowl. That way the geckos can climb in the bowl, eat what they want, and the dubia won't burry themselves. It also makes it easy to remove any uneaten roaches the next day as you just have to grab the bowl out. Lateralis are another good choice for roach feeders. They're a lot more active (more like crickets) and breed a lot faster. Either choice is far superior to crickets. Much higher meat to shell ratio, no bad smell, they live a LOT longer so you're not dealing with dead bugs all the time, no noise, and they're a more natural food source for most geckos. Roaches are native to almost every environment in the world...crickets are not. Also, tropical roach species won't thrive in your home if they get loose...crickets will. After many years of working with crickets, once I converted over to roaches, I never looked back.