Giant millipedes are great pets. However, even though the name suggests that they have a thousand feet, it is closer to 300 when they are fully grown. They are pretty easy to keep as pets, too. There are a few things that you need to keep in mind, though. So long as the terrarium that you have is more than twice as long as the longest millipede that you own, and the lid is not easy to remove. A screw top is one of the best that you can have, such as a sweet jar.
Use damp soil as a substrate to keep the humidity high, and keep them in a warm spot. Millipedes will eat almost anything that inorganic, such as dead leaves, food peelings, and even fish food mixed with the soil. One other thing to remember, though, is to give them calcium. The easiest way to do that is using cuttlefish. Providing that you keep the soil damp, there is no need to keep extra water in there for them.