Giant millipedes are herbivores, meaning they eat only plant matter, such as leaves and fruit. Unlike centipedes, they are not carnivorous and do not hunt. Instead, they peacefully meander around munching on whatever decaying leaves or fruit they happen to find. More specifically, they are actually herbivorous detritivores, which means that they eat decaying leaves and wood, rather than things such as fresh leaves or grass.
While the majority of their diet should be composed of decaying leaves from hardwood trees (maple, oak, walnut, etc) and decaying wood, giant millipedes will eat all manner of fruits and vegetables including melons, bananas, apples, cucumbers, peaches, carrots, and romaine lettuce (but not iceberg lettuce, as it doesn’t provide adequate amounts of nutrients). You’ll probably want to steer clear of peppers, garlic, onions, and anything that has been pickled however.
When deciding what to feed them, soft choices are best, especially if it’s stated to decay a little (for instance, a banana that’s begun to brown, rather than a fresh, firm apple). Fruits and vegetables should be peeled and/or sliced to make them easier to consume. Also, unless you grew them yourself, be sure to thoroughly wash all produce prior to feeding to make sure they don’t have any traces of pesticides!
How to feed your millipedes is very simple. Just place the food in their tank on top of the substrate and let them eat it as they please. You should feed them at most about once a day. The amount of food you should give them at a time will depend on how large they are of course, but generally just give them as much as they can eat in a day (but no more).
If you end up giving them too much food, it shouldn’t cause any major problems, as long as you remove it before you notice it starting to grow mold or attract pests. If you leave it in long enough to attract pests such as parasitic mites, they may infest the entire tank, requiring a complete replacement of the substrate to get rid of.
Millipedes Need Leaves and Wood
It’s important to remember that giant millipedes will not flourish with just fruit and veggies alone. They need leaves and decaying wood (both should be only from hardwood trees) in order to be happy and healthy. These make up an important part of their substrate and are vital when keeping them as pets.
You can collect leaves and wood from outside if you have hardwood trees (avoid soft wood trees like pines) nearby. Just make sure they haven’t been contaminated by pesticides (like from a nearby farm field for instance).
You should take care to remove any unwanted hitchhiker pests from the leaves and wood, to avoid infecting your millipedes and their enclosure. A simple visual inspection for any mites/insect eggs/etc is better than nothing, but baking the wood and leaves in the oven for a short time, or leaving them submerged in water for a while should basically have the affect of sterilizing them of pests.
When placing the wood into your millipede’s habitat, its best to shred the wood into small pieces and spread it around (remember, it should be wood that’s already started to decay, so it should be easy to break up by hand without needing to bust out a saw or anything).
If there are no hardwood trees nearby, you can instead purchase commercially available substrate composed of the proper blend of leaf/wood matter from various sources online.
Calcium for a Healthy Exoskeleton
Giant millipedes should also be provided with a source of calcium, as its important for the health of their exoskeleton (the hard, exterior “shell” of their bodies). Without this supplement to their diet, they will not be able to properly maintain their exoskeleton in top, healthy condition.
Providing the needed calcium isn’t difficult though. It can be in the form of a commercially available vitamin powder sprinkled onto their food, separately as a cuttlefish (like the kind commonly given to birds), or simply some crushed eggshells scattered about their enclosure.
It can also be a good idea to give them a little protein now and then in the form of fish food as another supplement to their diet.
Do Giant Millipedes Need Water?
Depending on the amount of moisture in their food, your millipedes will likely also need a source of fresh water. This water should be free of chlorine, so if you are on city water, rather than a well, you probably won’t want to use water straight from the tap.
It’s also important that the water is provided in a very shallow container, such as a shallow dish. Otherwise, the millipedes may have trouble drinking it, or could even end up falling in and drowning if they’re small enough!