Springtails, or Collembola, are primitive hexapods (six-legged arthropods) that are closely related to insects. These small critters (usually less than 3 mm) live in soil, leaf litter, and other damp organic material. The name “springtail” comes from an ability to spring forward, or jump, by releasing an appendage that is normally tucked under the abdomen.
There are Springtails in many sizes. There are small ones little more than 0.1 mm, and large ones; the largest species is 17 mm.
Every now and then you’re in luck, as in the photo below taken by Jan J. van Duinen. All of a sudden there are two species of springtails in front of your lens, both adults but very different in size. A big Dicyrtoma fusca and a small Sminthurinus aureus.
Springtails are ridiculously colorful, quite unexpected for an animal that’s only 1mm big.
Springtails also have interesting courting dances. Perhaps the most fascinating of these behaviors, called the “Cha-Cha-Cha”, involves males and females engaging in a courtship dance with the male and the female initially standing facing each other, head-to-head and performing a push-and-retreat ritual until a rhythm is established. As the female tries to spin away, the male immediately counters, hoping to woo the female into accepting him as a mate.
It’s not really a mating ritual given springtails do not ‘mate’. The male (the small specimen) deposits a sperm drop on a stalk (spermatophore). The female (the large specimen; in this case a yellow color variant) will take up the sperm drop. It might be better to call it a head-banging ritual.
I would encourage you to go to http://www.chaosofdelight.org to see Andy Murray’s wonderful gallery of springtail photographs.