Mine have never taken anything that hasnt moved on its own although that isnt to say that they would refuse it. I just never have tried as I believe making all aspects of their life as natural as possible, including their feeding. All the nutrients that they require are found in the healthy crickets / mealworms that I feed them, all the better if I gut load the crickets / mealworms prior. Using a supplement may seem convenient but isn't the natural / proper way to go. Supplements should only be exactly that, supplementing the feeding practice you need to have in place.