Why is an earthworm best to feed a bearded dragon lizard?

Earthworms can be part of a good diet for bearded dragons, which also eat crickets, silkworms, feeder roaches, chopped collards, mustard greens, dandelion greens, and turnip tops. Earthworms have a good calcium/phosphorus ratio (like silkworms), while crickets should be supplemented with calcium powder. Earthworms do pose a risk of transmitting capillaria parasite. Captive reptiles that eat live foods should be tested annually for internal parasites, as part of their regular annual vet checkup.