Mine are not big on earthworms either. They love the dehydrated mealworms but only play around with live earthworms. They'll grab a mosquito out of the air and will go after some ground bugs, but not all of them.
Mine love dried meal worms, and every kind of bug or creepy crawly they can get their beaks on!!! I love watching them jump half way up the fence, pluck a grasshopper and land like a ninja on the run!
I have some that will eat them and some that act like they don't even see them when I offer them. It's just differences in the birds. But ALL my birds will eat mealworms.
@Jerseycoop: The ones of mine who will eat them suck them up like spaghetti too. It's pretty funny
I've never seen mine go after worms. I didn't know about meal worms. They do love every kind of bug they can find. I've watched them picking mosquitos right out of the air. They do enjoy japanese beatles. I've set up a beatle trap that uses no pesticides, just a sexual and scent lure so that I can give them to the girls.