The Zophobas Morio worm is more commonly called a super worm... It is not really a worm at all but actually Larva of the zophobas morio beetle. Since they are such a ravenous eater they can be gutloaded very easily, making them a great choice for a feeder. As far as if you could them them to your Yemen... I usually wait until the Cham is Juvie sized to occasionally feed them. I worry about small babies digesting them. If it is an adult Yemen... Gutload them(their nutrional value alnoe is pretty low), and feed away. With adult Chams I will feed them a few during a feeding...along with whatever else I offer. I wouldn't recommend a diet of only SuperWorms... Variety is the best way to go.