As has been stated, their waste does not smell bad. I would say that their frass is some of the least offensive -- just further broken down plant material. The texture is not offensive either -- whereas I wouldn't ever intentionally touch vertebrate waste -- eww!
The significant decay is key. Is it soft enough to easily scrape off with a nail? I have had wood this soft that was pale, gray, reddish, and dark brown -- probably depends both on the type of wood and what flora and fauna have been degrading it. I believe only black wood is no good as it is either burnt or completely rotten. Oh, and wood from hardwood/deciduous plants is best, although if well-decayed, the volatile oils of pines and other conifers have probably been broken down.
I would say yes -- or what else would it be covered in? How deep the substrate should be depends on both the enclosure and type of millipede that you are keeping. For a 10 gallon tank, I think 3-5 inches of substrate would be good. You might have the bottom inch composed largely of coconut fiber to help you monitor the moisture level. The type of lid you need depends on the millipedes. Desert species such as Orthoporus ornatus need high ventilation. Most millipedes will do better with very low ventilation and this also makes your job easier as once you get the substrate just moist, it should be very slow to dry out if your ventilation is low (although heaters also speed up drying of substrate).
Let us know if there are specific species of millipedes that you are considering as then we can focus advice on their specific needs.
For most millipedes, I would recommend half decayed hardwood/crushed leaves and half coconut fiber/organic fertilizer-free potting soil -- all components mixed together, not layered. For flat and feathered millipedes, it will be different, depending on species.
@ErinM31, I couldn't have said it better myself.As has been stated, their waste does not smell bad. I would say that their frass is some of the least offensive -- just further broken down plant material. The texture is not offensive either -- whereas I wouldn't ever intentionally touch vertebrate waste -- eww!
I have not heard of anyone developing an allergy to millipedes but in seems possible to develop an allergy to anything. I would not recommend holding millipedes too often in any case -- many find it stressful and many species will release defensive fluids upon even gentle handling. (I have not found these fluids to be irritating, but they do discolor the skin for a few days. Polydesmidan (flat millipede) defensive secretions are more volatile and I try to breathe as little of it as possible when I have to move them. I may have gotten a headache from transferring a large number of Auturus evides to a new enclosure or it may have been unrelated.
I have not used a heating pad with my millipedes as those I keep are temperate and fine with night temperatures in the upper 60's. If you do use a heating pad, make sure it is an appropriate wattage for both the size and material of your enclosure (lower wattage may be safe for plastic but I feel more comfortable only using them on glass). Also, be sure to put it on the side of the tank and not under -- millipedes and indeed most animals will burrow to escape temperatures that are too hot. As for how long it should be on, that depends on what temperature range you need to maintain. Whatever you do, I think it is best to maintain a circadian rhythm of warmer temperature during the day and cooler at night. So for some of my roaches that reproduce more successfully at 80F+, I have the heating pad on only during the day except on really chilly nights, when I leave it on to limit how low the temperature of their enclosure drops.
The significant decay is key. Is it soft enough to easily scrape off with a nail? I have had wood this soft that was pale, gray, reddish, and dark brown -- probably depends both on the type of wood and what flora and fauna have been degrading it. I believe only black wood is no good as it is either burnt or completely rotten. Oh, and wood from hardwood/deciduous plants is best, although if well-decayed, the volatile oils of pines and other conifers have probably been broken down.
I would say yes -- or what else would it be covered in? How deep the substrate should be depends on both the enclosure and type of millipede that you are keeping. For a 10 gallon tank, I think 3-5 inches of substrate would be good. You might have the bottom inch composed largely of coconut fiber to help you monitor the moisture level. The type of lid you need depends on the millipedes. Desert species such as Orthoporus ornatus need high ventilation. Most millipedes will do better with very low ventilation and this also makes your job easier as once you get the substrate just moist, it should be very slow to dry out if your ventilation is low (although heaters also speed up drying of substrate).
I hope that helps!
I don't see why not -- my millipedes have eaten ivory, red and dark brown colored wood. I think offering a variety is healthiest but I don't see why this soft white decayed wood couldn't serve as your staple.
It very well might attract mold but this is actually not a bad thing as it makes the wood even more edible for the millipedes. Springtails can help keep the mold in check. I usually put a small layer of coconut fiber or similar inert material over such mold when I see it but that probably does nothing except to make me feel better psychologically, lol!
I don't have experience with that species (I mostly have species native to the U.S.), but there are many on this forum who do.
I would recommend having a look over the threads to see what people have tried, what has worked and any problems that have been run into.