What are Superworms?
Superworms are the larvae of Zophobas morio, a type of darkling beetle. They may seem similar to mealworms, which are another type of darkling beetle, but they are in fact entirely separate species!
Superworms are a common feeder insect for insectivorous and omnivorous reptiles, amphibians, and other pets.
How to House Your Superworms
Superworms don't need much in terms of housing. Small numbers of them can be kept in a 4" x 6" cricket keeper or similar, but larger numbers (more than 100) will need something larger, like a 5 or even 10 gallon tank or a tub of comparable size.
There is little danger of the worms themselves escaping, as they prefer to stay buried, but if you have any turn into beetles, you will want a ventilated lid to keep them from roaming about your house.
Superworms should be kept at room temperature and never refrigerated, as the cold will kill them.
How to Feed Your Superworms
For superworms, their bedding doubles as their food. Oatmeal and oat bran are popular choices, and your superworm tub should have at least a couple inches of it for the superworms to burrow in and eat. However, what you feed to your superworms is eventually what you feed to your pet, so grain is not enough. It's best to add fresh vegetables to the superworm tub for an additional source of vitamins.
As the superworms eat through their bedding, they will produce droppings (called "frass") and shed skins. Over time, the frass and shed gradually replace the bedding. Check the composition of the bedding on a regular basis, and when you notice levels getting low or significant buildup of waste, add more bedding. It's a good idea to do a total replacement every so often.
Keeping Your Superworms Hydrated
Another reason to provide fresh vegetables to your superworms is for hydration. Aside from vitamins, vegetables are full of water, and provide a way for your superworms to get water without potentially drowning in a water dish or making the bedding soggy. Use nutritious vegetables like carrots, broccoli, sweet potato, and squash, and remove them when they've dried out or start to mold.