Although they have six legs, springtails are not insects. Among other things, their mouthparts are hidden inside their head, while the mouthparts of insects are on the outside of the head and are easily discernible.
Springtails are small, wingless arthropods whose shape, size and colour vary greatly according to species. Most measure less than 3 mm long, but some can be as long as 1 cm. They have in common a fork-shaped appendage under their abdomen called a furca, which allows them to jump into the air. It is reduced or absent in many species. Another organ specific to springtails is the collophore, or ventral tube, which is used to suck up liquid and attach itself to smooth surfaces.
Springtails have an oval head and one pair of antennae. Each side of the head has one to eight pairs of simple eyes. Some species do not have eyes. The mouthparts vary greatly in shape. Those used for chewing are always hidden inside their heads.
The colouring of springtails varies from white to almost black, with many colours in between : yellow, orange, pink, red, green, blue, indigo… Those that live above ground are usually more brightly coloured.
Springtails are an ancient group of animals. The oldest fossils of these arthropods date back 380 million years, during the Devonian period, before dinosaurs appeared on earth. Fossilized specimens that are more than 380 million years old correspond to genera and even species that are still alive today.
Springtails can jump to a height of 50 to 100 times the length of their bodies. Some species can jump as high as one metre. They execute these acrobatics with a structure that holds their tail under tension like a spring, which is where their name comes from. Springtails jump to escape from their enemies quickly. Otherwise, they walk on the tips of the claws at the end of their legs.