springtail

Springtails, or Collembola, are a group of tiny, wingless hexapods that live in soil and leaf litter. Although often called insects, they are not true insects; they belong to the non-insect hexapods within the larger arthropod group Entognatha. With roughly 8,000 described species, springtails display a wide range of forms and sizes, most commonly 1–2 mm in length, though some species reach several millimeters.

A hallmark of springtails is their furcula, a forked jumping organ tucked under the abdomen, which is held in place by a retinaculum. When released, the furcula propels the animal into a jump. They also possess a ventral tube called the collophore on the first abdominal segment, which aids in water uptake and osmoregulation. Many species have reduced eyes, and body shapes range from slender to globular; waxy cuticles help limit water loss in dry conditions.

Ecologically, springtails inhabit moist soils, leaf litter, moss, rotting wood, and other detrital habitats worldwide. They feed on decaying organic matter, fungi, algae, and bacteria, contributing to decomposition and nutrient cycling. Some species are omnivorous or predaceous on microarthropods. Reproduction varies: many species reproduce sexually, while parthenogenesis is common in others. Eggs hatch into juveniles that resemble adults, and several molts produce the adult form.

In human contexts, springtails are generally harmless to people. They are valued as bioindicators of soil health and moisture, and are often used in ecological and soil-physics studies. High indoor populations usually indicate damp conditions rather than a direct threat.