Springtails are one of the most numerous hexapods as measured by numbers of individuals. Although related to insects, springtails (Collembola) are grouped with insects and other six-legged arthropods in the Hexapoda. Collembola share a six legged state with insects, but other parts of their morphology and physiology differ. Most notably, Collembola have a “ventral tube” something no insect has. Collembola are named for this characteristic: Colle (Greek for “glue”) and embolon (Greek for “piston”). All Collembola have a “glue piston” a versatile organ that has several uses. The ventral tube has a sticky coating that is used to transfer a water repellent coating to the cuticle. The ventral tube is long enough to reach most areas of the body.
When a Collembola finds itself on its back, the sticky ventral tube can be used for righting. An upside down springtail will extend its ventral tube around its body to the substrate. The sticky ventral makes an anchor the springtail can use pull against as it rolls over into an upright posture.