at herpfood.com they are closely related to the Trevo worm, some say they are a trevo worm but from what i have found out they are not,i could be wrong, in the same family perhaps? all i know is that they are a really great alternative to waxies as a treat, i feed them more often and in larger quantities then you would a treat as they are the feeder that contains the highest calcium. They are a softbodied pinkish orange worm that smells like buttered popcorn, no joke, if i were in out in the wild with no food, these guys would be easy to snack on =P Silks on the other hand make an excellent main protein source as they are soft bodied and high in calcium also and low in fat, with both worms the downside is the cost, but i wouldnt have my dragons do without them =)