How Long Do Millipedes Live? Lifespans by Species

The honest answer depends enormously, and not in the way most people expect. The range across the animals I keep runs from under three years to comfortably over ten, and the thing that decides it is not how big the millipede gets.

Worth settling before you buy, because a millipede is not a short commitment. If you pick well you may still be looking after the same animal when the tank it started in has been replaced twice.

The giants: roughly seven to ten years

The large tropical species are the long-lived end. Oakland Zoo, cited in the reference material on Archispirostreptus gigas, gives giant millipedes a life expectancy of about seven to ten years. This is the African Giant Black, the animal reaching 33.5 cm at the documented extreme and carries somewhere around 256 legs.

The Ivory sits in similar territory in my experience, which is why the listing says you can expect it to still be around a decade from now. These are animals you buy once and keep for a long stretch, and the substrate you set up on day one matters far more than it would for something that lives eighteen months.

The mid-size species: around five years

Below the giants, the medium species tend to land nearer half that. Five years is a reasonable working figure for a mid-size tropical millipede kept warm, damp and undisturbed, which still makes it a longer commitment than most reptiles' feeder animals and many small mammals.

This is the band most first millipedes fall into, and it makes a sensible starting point precisely because five years is long enough to learn the animal without being a fifteen-year decision made on a whim.

The short end, and the one that surprises people

The British flat-backed millipedes run on a completely different clock. They take between two and three years to reach breeding age, and then the adults die once they have bred. No long retirement waits at the end of it.

I have written that up separately because it catches people out, but the short version for planning purposes is this: with a flat-back you are keeping a population that turns over, not individuals that persist. If you want an animal you will still be looking at in 2035, this is not it.

The Pink Dragon sits at the short end too, for different reasons, and it is worth reading a species page before assuming any small millipede is a long-term animal.

Why they take so long to get there

Millipedes do not hatch as small versions of the adult. They hatch carrying three pairs of legs and only a handful of body rings, then build the rest of themselves one moult at a time. A hatchling is not a miniature adult waiting to inflate. Most of the animal simply does not exist yet.

That is the reason growth is measured in years rather than months, and it is also why calcium is not optional. Every moult rebuilds the exoskeleton, so every moult draws on a calcium supply that has to be sitting in the enclosure. A millipede short of calcium does not merely grow slower. It moults badly, and a bad moult is one of the few things that will kill an otherwise healthy animal outright.

What actually shortens a millipede's life indoors

In my experience almost every premature death traces to one of four things, and none of them is exotic.

Heat from underneath. A mat beneath the enclosure kills more millipedes than anything else I know of. They burrow to escape conditions they dislike, so heating the floor takes the refuge away and cooks them where they went to feel safe. If warmth is needed, it goes on the side or above.

Softwood. Pine and other conifer material does not agree with millipedes, and it turns up in cheap substrates and in bark bought for reptiles. Hardwood only.

A shallow bed. Substrate is food and shelter at once. A millipede in five centimetres of coir has nowhere to go and little to eat, and it will decline slowly in a way that is easy to miss until it is too late.

Being disturbed. This is the one keepers cause with good intentions. Digging down to check on an animal that is mid-moult is a good way to end it, since a freshly moulted millipede stays soft for days and marks easily.

What this means when you are buying

You will rarely be told an animal's age, and with a millipede you often cannot tell by looking, since a sub-adult of a large species can be bigger than an adult of a small one. Two things follow from that.

First, buying juveniles gets you more years, at the cost of waiting for size. Second, if a seller offers a large adult of a long-lived species cheaply, it is worth asking how old it is, because you may be buying the last two years of a ten-year animal.

The same logic applies to the enclosure. A five-year animal earns a substrate built right the first time, because you are not going to want to strip and rebuild a settled bed three years in. Deep, hardwood-rich and left alone is the whole method, and it costs no more at the start than doing it badly.

Neither is a reason to avoid adults. It is a reason to ask, and to treat a millipede as something you take on instead of something you try out. If you want to browse by what suits the commitment you have in mind, the millipede range spans all three bands.