One might easily mistake these tiny critters for insects, but they are not. They belong to a class of wingless, minute arthropods called Entognatha, which has 3 orders covering Proturans and Diplurans, and Collembola, the springtails. They are a primitive species, and occur in vast numbers in soil, leaf litter and fungi, and hundreds of thousand maybe found in one square metre. Springtails are unquestionably the most abundant arthropods in the world. There are about 250 different species in the UK.
Springtails can be elongated or globular in morphology, with hairs or scales. The body can be divided into three main regions, starting with the head. The eyes are simple, and the antennae usually have four segments or more. The mouthparts retract when not in use. The thorax has three segments each with a pair of legs. The abdomen has six segments, although in some species some of these maybe fused together, and beneath is a forked springing organ which helps them propel themselves away from potential harm. All springtails are defined by the ability to glue themselves to smooth surfaces via a tube which appears from the first abdominal segment. Collembola, derives from the Greek words ‘cole’, meaning glue, and ’embolon’, meaning piston. Some also use this tube for grooming purposes.
Found in many varying habitats, peering under rocks and stones, and gently poking amidst leaf litter, humus or soil, one may see these for a brief moment before they spring away on their tails. In their evolution they never possessed the ability to fly, but the furca, the spring organ, certainly propels them through the air. They feed on fungal hyphae, and organic detritus in the soil. Some species graze on algae and lichens from the bark of trees, whilst others predate on other Collembola. They go through various stages of molting before they become adults, and even after sexual maturity they continue to molt.