Whether you're using your compost worms for fishing or selling the worms to gardeners, fat worms are most desirable. Fattened compost worms are evidence of healthy feeding and high-quality compost. You can use a variety of commercially made worm food blends to fatten up your compost worms, particularly the "worm chow" blends that are high in protein. You can also make your own worm-fattening food using a simple recipe and modifying your worms' food-scrap diet.
Feed your compost worms lots of green vegetables. Limit starches and highly acidic fruits and vegetables.
Place 12 egg shells into a blender. If you're using egg shells from cracked raw eggs, be sure to rinse the shells well in warm water and let them dry. Blend the egg shells until they're pulverized into a powder.
Add 2 cups of oatmeal and 1 cup of cornmeal to the blender. Blend the cornmeal and oatmeal with the pulverized egg shells.
Sprinkle the mixture on top of your compost until you've created a thin layer. Mist with water and cover your compost bin. If you usually leave your compost uncovered, spread a layer of moistened newspaper over the grain mixture.