Springtails (
Collembola) form the largest of the three lineages of modern
hexapods that are no longer considered
insects (the other two are the
Protura and
Diplura). Although the three orders are sometimes grouped together in a class called
Entognatha because they have internal
mouthparts, they do not appear to be any more closely related to one another than they all are to insects, which have external mouthparts.