Eating dirt

Oh, what you tell is nothing. My girl budgie (3 year old) loves to empty the dirt from the potted plants. Both the male and female eats the dirt. It keeps their tommies working, I think. She kikcs the dirt out, like a dog and she is amazingly effective. When I give them basil i pots, they eat the pland AND the dirt. Right now she is having eggs again (she is a machine there) she is digging like a frantic.