Insects are known to be excellent sources of protein. In fact, lots of animals depend on them for survival in the wild. If you are taking care of reptiles, then you might be interested in getting feeder crickets for them. A regular diet of these will help them grow quickly and maintain their health. Use it as part of a rotation that may include worms and other suitable nutritional items.
Just be careful when buying these. Most are grown in farms and shipped to buyers across the country. The process can take its toll on these creatures with some not making it alive to the recipient. Check for feedback from other pet owners to see which of the sources provide the best results. Of course, you will also have to consider the pricing since the purchase of these crickets is likely to be a long-term commitment.