Soil mites (Acari) are the most diverse arthropods in soil — tiny, armored, and everywhere. They are not the mites that eat your plants. Those are spider mites, a different family with a different agenda (see our spider mite guide if that is your problem). Soil mites are the cleanup crew.
The two main kinds
Oribatid mites — sometimes called beetle mites for their hard shells — shred leaf litter and graze fungi. They are slow, armored, and ancient: oribatids have been farming fungi for millions of years, and their droppings (frass) are microbe-rich soil food in their own right.
Predatory mites hunt nematodes, springtails, and smaller mites. Some predatory mites are sold as biological control for thrips and spider mites — the same family, working for you above ground and below.
Why they matter
Mites connect the layers: they shred what fungi can’t finish alone, they carry fungal spores and bacteria on their bodies (tiny farmers, spreading inoculum as they walk), and they feed larger predators like beetles. A soil with diverse mites is a soil with a working food web — and oribatid mites are so sensitive to disturbance that ecologists use them as indicators of soil health.
How to keep them
- Don’t till. Tilling crushes armored mites and shreds their habitat.
- Mulch and litter. Mites live in the litter layer. No litter, no mites.
- Skip broad-spectrum sprays on soil. They kill the cleanup crew along with the target.
Meet the rest of the underground workforce in the Soil Food Web Explorer.
🌱 Keep learning
Three related guides worth reading next:
- Living Soil — A field guide to everything alive in your dirt: bacteria, fungi, protozoa, nematodes, worms, and the whole food web.
- Soil Microbiology — Meet the billions of microbes doing the real work under your feet.
- Organic Matter: The Pantry — The pantry the entire soil food web eats from — fallen leaves, dead roots, compost, and why it matters more than any fertilizer bag.