Not everyone thinks worms are icky. Nonaggressive, helpful to the environment and easily owned, they are great pets for lovers of invertebrates. If you're going to keep earthworms, feed them exactly what they eat in nature -- mostly microscopic organisms that inhabit soil.
Food for Worms
Lacking teeth, earthworms depend upon food that really can't be seen by the naked human eye, such as protozoans, nematodes, rotifers, bacteria and fungi in the soil. And even though it sounds gross, earthworms will find nutrients on decomposing animals they come across on their travels. Even though most remains are too big for earthworms to consume outright, they will moisten them to make them easier to fit into their worm mouths.
The deepest burrowing earthworms (known as the Anecics) survive completely on soil -- but because they live and move in deeper soil, they come across bacteria and organisms that are invisible to you and me.
How Do They Eat?
An earthworm's mouth is called its prostomium; it is pointed and hard. This helps them to burrow and press into crevices to consume dirt and decayed leaves and vegetation. The food they find is stored in a crop similar to a bird's, which holds the food until it is ground up by small bits of grit or sand that remain there to help digest food. Because of their gizzards, earthworms are able to digest food that other animals cannot: the gizzard breaks food down to the base nutrients that the earthworms can pass through their small intestines.
What Can I Give Them?
To help feed your earthworms, focus on providing as many microscopic organisms as you can. This means kitchen scraps, compost from your trash or lawn, and freshly dug soil. But a number of foods you absolutely cannot feed earthworms.
Do Not Feed:
- Meat and bones
- Salty foods
- Processed or fast food
- Mowed or cut green grass
All of these will be very toxic to your earthworms. Meat and bones are not only difficult for worms to process but will also attract predators and flies. Salty foods, feces, alcohol and citrus are all toxic to earthworms; they could kill them. Cut green grass has thermodynamic properties that can raise temperatures to unlivable levels for earthworms.
To help, put the earthworm food in one corner of the pen or container. You can see what the earthworms prefer.
Your pet earthworm will flourish and grow fat on a diet of healthy new soil, rotting fruits and vegetables, and even nonfood items such as junk mail, cardboard, egg cartons and dried leaves.