Millipedes
Deep substrate, high to moderate humidity, detritus-heavy environment.
Go with the Straightforward Choice for a simple cleanup crew or the Advanced Ecosystem suggestions to take your bioactive ecosystem to the next level!
Straightforward Choice: Springtails
Folsomia candida (Common White Springtails) for moderate humidity enclosures, Pseudosinella rolfsi (Runner Springtails) for humid enclosures.
Advanced Ecosystem: Springtails
Maximize biodiversity: Mix Thalassaphorura encarpate, Ceratophysella isabella, Lepidocyrtus sp, Pseudosinella rolfsi, etc. See the full species information list for picking additional springtails and to learn which environmental niche each species specializes in.
Straightforward Choice: Isopods
None (Do not use isopods).
Advanced Ecosystem: Isopods
None (Do not use isopods).
Quantity
Millipede enclosure size varies widely by species, but using a 10 gallon enclosure with deep substrate as an example, as few as 50 springtails per species could seed the enclosure. For the 10 gallon example I recommend 300-500 springtails if they are needed immediately.
Crucial Information
Do not keep isopods with millipedes! Isopods can eat millipedes alive when they molt. Avoid the springtail species Pseudosinella violenta as they could grow into an overwhelming population size in the detritus-rich millipede enclosures.
Additional Information
Millipedes require detritus rich substrate which doubles as food for springtails. Springtails may grow into high populations in humid millipede enclosures, and the very fast breeding species Folsomia candida could grow into an overwhelming population size. It is best to use F. candida for moderate-humidity enclosures to keep the population in check.