Wednesday, May 2, 2007

Housing Millipedes

Housing Millipedes

Millipedes are not as active as the faster centipedes and do not require as much room. A two-and-a-half or five gallon glass aquarium provides adequate space for even the largest of the giant millipedes. As a rough rule of thumb, you will want a tank that is at least as wide as your millipede is long, and at least one and a half times as long as the length of the millipede

Millipedes are not capable of climbing up glass or smooth plastic, but they are capable of using the claws on their feet to grip the bead of silicone glue inside the corners of the tank, and climb up and out. Your millipede cage will need a securely locking lid. The commercial fluourescent hoods that are used with fish tanks are not suitable for a millipede tank. Millipedes are much stronger than they appear, and are capable of wedging their heads underneath even the heaviest lids and leveraging it open enough to slip through.

The best kind of lid for a millipede tank is a screen mesh lid with metal clips to hold it on tightly, often sold for keeping reptiles and small mammals. Make sure the wire mesh is tight enough to prevent the millipede from squeezing through the holes. Note that the sharp wires used in these cages do present a potential danger to the millipede, which can sometimes cut its exoskeleton on these wires and bleed to death. Another type of aquarium top, also used for reptiles and rodents, consists of a perforated metal sheet with two rotating latches at either end. These latches hook underneath the lip that runs around the top of the aquarium to hold it on. This type of screen lid is less suitable for keeping millipedes---the metal is too flexible in the middle and a determined millipede, if it is able to reach the lid, will be able to wedge its head between the lid and the aquarium rim and escape.

The best option for housing a pet millipede is one of the clear plastic sweater boxes that can be found in any department store. These come in a variety of different sizes, and all have their own lids that snap on securely. They are also lightweight and take up a bit less room than an aquarium. Another advantage of the sweater boxes, particularly if you will be keeping a number of invertebrate pets, is that they can be securely stacked atop one another to put a large number of cages in the smallest possible area. One disadvantage of the sweater box, however, is that the plastic isn't as clear as glass, which may make your pet difficult to see.

Sweater boxes must be modified a bit before they make a suitable home for your millipede. Millipedes cannot tolerate damp stagnant air, so you will need to drill a large number of airholes for ventilation, along the top and bottom edges all around the box. This can be done with a hand drill, or the holes can be carefully melted through with a heated screwdriver or soldering tool. The holes should be no larger than half the body width of the millipede, to prevent escapes. If your millipede cage does not have adequate ventiliation, the warm damp conditions will encourage mold and fungus growth that will ruin the cage and present a danger to your millipede. Also, if the humidity level is too high, it will interfere with the diffusion of air into the trachea.

The final option for housing your millipede is one of the plastic "critter cages" that can be found in pet stores. These are available in a variety of sizes. Make sure you get a model that has little latches to hold the lid on securely---the cheaper versions have flimsy snap-on lids that often come apart whenever the cage is picked up by the handle. Millipedes are inoffensive scavengers and do not present any danger to each other. They will live happily together, in the same tank, in small colonies consisting of six or seven individuals. Provide the colony with a tank of at least ten gallons capacity so each has room to wander around and establish its own hiding place. Baby millipedes can be safely kept in the same enclosure as their older relatives.

Although different species of millipedes will not bother each other and can be kept in the same tank, there are some cautions that need to be considered. Millipedes from different geographic areas may have slightly differnet habitat preferences, and it may be difficult to provide optimal conditions for all of them in the same tank. In addition, animals from one area may have been exposed to pathogens or internal parasites that the others have not been, and have no natural immunity to. It is remotely possible that one of your millipedes may introduce a health problem that will wipe out the others. To play it safe, it may be best not to mix different species together in the same tank.


Millipedes dry out very easily, and require damp and warm conditions. The substrate in their cage must be kept slightly moist. If you go to the woods, move aside a bit of leaf litter and stick your finger into the exposed black soil, that is about how damp the substrate in your terrarium should be.

The most practical and useful substrate for a millipede tank is a 50-50 mixture of sterilized potting soil and peat moss, which can be found at any garden store. Line the bottom of the tank with about four inches of this mixture, and cover it with a thin layer of leaf litter or terrarium moss. Millipedes are inveterate burrowers, and this substrate will soon be criss-crossed with a network of tunnels and chambers. Very young millipedes in particular spend almost all of their time underground, where they avoid predators while they are eating and growing.

Cover the top of the soil/peat moss substrate with a very thin later of bark chips or leaf litter to help keep it damp. As it dries out, the top of this substrate will need to be periodically misted again. It is best to heavily mist just a corner of the terrarium and mist the rest just enough to keep it damp, allowing the millipede to choose the moisture level it wants. If you begin to see fuzzy white patches that look like cotton, it is fungus and it means that you are spraying the tank too much and making it too damp, or that there is not enough airflow and ventilation.

Over time, a deep layer of feces will build up in your millipede tank. This will decompose and form a crumbly black humus. This layer of rotted feces may sound unappealing, but it does not normally present any odor problems. Since young millipedes are coprophagous, the substrate in any tank that contains babies should not be changed. Even in tanks that house single millipedes and do not have any young, it is not necessary to change the substrate so long as it is kept free of fungus, mites and other pests.

Hiding Spots

Millipedes are nocturnal and hide during the day, emerging at night to forage for rotting vegetation and plant material. Your millipede will need a secure place where it can sleep during the day. This shelter is also important for conserving water: by pressing its body against the walls of a damp shelter, the millipede reduces the amount of water vapor it loses through evaporation, and thus conserves its body moisture.

A suitable shelter can be made by using aquarium silicone to cement a number of flat rocks together to form a shallow cave. An overturned piece of bark is also acceptable. The inside of the shelter should have just enough space for the millipede to curl up with its body touching all the walls at the same time. Mist the underside of the shelter occasionally to keep it damp inside.


Millipedes inhabit cool damp forest floors and do not need as high a temperature as some of the other triopical arthropods. Temperate North American species of millipedes, such as Narceus, can be kept at ordinary room temperatures and do not require any supplemental heat.

The larger tropical millipedes found in the pet trade need somewhat warmer conditions. Daytime temperatures of 80-82 degrees are suitable, as long as the millipede has a damp hiding spot to spend the day.

Some keepers use an incandescent light bulb, placed outside the screen lid and focused insdie the tank, to warm the interior of the cage. There are potential problems with this method, however. It tends to dry the cage out rapidly, which can be lethal for moisture-loving millipedes.

Another option for heating is the undertank heater commonly used for lizards and other small reptiles. These look like flat pads that stick onto the bottom of the cage and are heated electrically. The heat diffuses through the substrate to produce warm temperatures. They are the best method of heating a sweater box type of cage. The heater should be placed so it covers about one fourth of the bottom surface, at one end of the cage. Place shelters both at the warm end and at the cool side, so the millipede can move securely from warm to cool as it wishes.

Undertank heaters also present some safety problems, however. They tend to make the bottom of the substrate warmer and drier than the top, an unnatural condition. In the wild, millipedes escape from conditions that are too warm and dry by digging deeper into the soil. In a cage using an undertank heater, they will stick to this inborn behavior, even though in this situation burrowing more deeply actually exposes them to even more heat and dryness. You will need to mist the cage often to keep the substrate damp.


Tropical millipedes are creatures of the rainforest floor, where they lurk among the leaf litter and debris. The thick canopy of leaves filters out most of the sunlight, and as a result the forest floor is a dim and unlit place even during the height of the day.

In captivity, millipedes prefer subdued lighting. Usually, the ambient light levels inside your house will be sufficient. No lighting is needed for the cage itself.

If you use an incandescent light bulb as a heat source, make sure it is colored blue or red. These wavelengths cannot be seen by millipedes, and they will act as if it were dark. This is also useful if you want to observe your millipede during its nocturnal activities.


Your millipede should be provided with a large flat water dish for drinking. The evaporation of water from the dish will also help maintain the proper humidity level in the tank. Millipedes cannot swim, so you will need to fill the water dish with pebbles to prevent the millipede from falling in and drowning. Make sure the sides of the dish are low enough for the millipede to climb out easily.

No comments: