Bioactive Cleanup Crew Guide: Springtails and Isopods Explained

The short answer: a bioactive cleanup crew is two groups of small animals, springtails and isopods, living in the substrate. Springtails are tiny (about 1/16 inch) hexapods that feed on decaying plant material, fungi, molds and algae; isopods (pillbugs and sowbugs) are land crustaceans that mainly eat decaying plant material. Together they break down leaf litter, mold and leftovers so the substrate does not sour. They do not replace you: the substrate makers still tell you to spot clean where the animal defecates. Start with one culture of each, keep at least part of the substrate damp, and keep a layer of leaf litter on top as their food.

The biology below comes from university extension services (UC Statewide IPM and Penn State Extension), and the setup advice from the substrate makers' own instructions. Ask a reptile veterinarian if your reptile seems unwell.

Springtails and isopods compared

The two cleanup crew groups (UC IPM and Penn State Extension)

	Springtails	Isopods (pillbugs and sowbugs)
What they are	Wingless hexapods, order Collembola	Land crustaceans, order Isopoda
Size	About 1/16 inch (UC IPM); species range from 0.2 to 10 mm (Penn State)	Adults about 1/3 to 3/4 inch; newly emerged young about 1/12 inch
Food	Decaying plant material, fungi, molds, algae; also mildew and bacteria (Penn State)	Mainly decaying plant material
Moisture	Need high humidity and die without moisture	Live under damp litter and debris; drier soil reduces them
Breeding	Not covered in these sources	Eggs carried in a brood sac, hatch about a month later; young stay in the sac about 2 weeks
Life span	Not covered in these sources	Adults live 2 to 5 years
Harm to people or pets	"Will not bite or otherwise harm people or pets" (UC IPM)	Described as a nuisance indoors, not as harmful (UC IPM)

What springtails do

Springtails are the mold control. UC IPM describes them as very small, wingless, jumping creatures that feed on decaying plant material, fungi, molds or algae, and that use a forked structure folded under the abdomen, the furcula, to spring into the air when disturbed (UC IPM). Penn State Extension adds mildew and bacteria to the menu and says springtails "require high humidity environments" such as leaf litter and mulch (Penn State Extension).

That diet is why springtails earn their place: mold on wood, leaves or damp soil is springtail food. Their need for moisture is also the limit. UC IPM says they soon die indoors unless they find moisture, so in a dry desert enclosure they survive only where the substrate stays damp.

What isopods do

Isopods are the bigger shredders. UC IPM calls pillbugs and sowbugs soil-dwelling crustaceans in the order Isopoda that mainly eat decaying plant material and help break down organic matter (UC IPM). Adults are about 1/3 to 3/4 inch long and live two to five years. Females carry their eggs in a brood sac; the eggs hatch about a month after they are produced, and the young stay in the sac for about two weeks, then molt every one to two weeks for several months as they grow.

The two common kinds are easy to tell apart: pillbugs curl into a ball like a pill when disturbed, while sowbugs cannot roll up and run away instead, and have distinct appendages sticking out at the rear (UC IPM). UC IPM's advice for getting rid of them in gardens, keeping the soil surface drier, tells you what they need in an enclosure: damp substrate under a layer of litter.

What a cleanup crew does not do

• It does not remove the need to spot clean. The Bio Dude says its substrates still need spot cleaning in the areas the animal uses (The Bio Dude), and the RSPCA says to spot clean waste as soon as it appears (RSPCA).
• It does not make the substrate permanent. Josh's Frogs says to stir the surface of its BioBedding every 1 to 2 weeks and replace it after several years (Josh's Frogs).
• It does not live on air. Leaf litter is its food and cover. The Bio Dude says leaves and other biodegradables break down in about 2 to 3 months in tropical setups and 3 to 4 months in arid ones, so top them up.

Dry versus humid enclosures

Both groups need moisture, so a tropical enclosure is easy and a desert one needs a plan. In a humid build with a substrate such as Josh's Frogs Tropical BioBedding, the whole floor suits them. In a desert build, The Bio Dude says its Terra Sahara is designed to hold water while allowing evaporation (The Bio Dude), and suggests keeping the substrate damp in the areas the animal uses as a toilet so the cleanup crew works faster there. That damp patch, under leaf litter and away from the basking spot, is where the crew will live.

Keeping a cleanup crew alive by setup type

Setup	Where the crew lives	What to do
Tropical (crested gecko, tropical snakes)	Throughout the substrate and litter	Keep the substrate moist to the maker's squeeze test; top up leaf litter
Desert (bearded dragon, leopard gecko)	Damp lower layers and damp patches under litter	Keep waste areas damp, as The Bio Dude suggests; leaves break down more slowly (3 to 4 months)
Snakes and burrowers (ball python)	Throughout a damp, deep substrate	Moisten to saturated but not dripping, per The Bio Dude's Terra Firma guide

How to add a cleanup crew

1. Finish the substrate and leaf litter first; see our guide to setting up a bioactive enclosure.
2. Add one culture of springtails and one of isopods directly to the enclosure, as The Bio Dude instructs (The Bio Dude).
3. Run the enclosure before the animal goes in; the RSPCA advises a week for a new crested gecko enclosure.
4. Keep at least part of the substrate damp and the leaf litter topped up.
5. If you stop seeing either group, check the moisture first, since both need damp conditions (UC IPM; Penn State), then add a fresh culture.

Live springtails and isopods are sold by invertebrate breeders and are not sold through the links on this site. Leaf litter is:

If you collect leaves yourself, the Merck Veterinary Manual recommends oven baking natural leaf litter, soil and sand before use to sterilize them (Merck).

Next steps

The crew needs a home that holds damp substrate: see the best bioactive substrates and the best bioactive enclosures, and size the layers with our substrate calculator.