Spider veins are tiny, thin veins that can be seen very close to the skinâs surface. They look like red, blue, or green spider webs just beneath the skin. Sometimes they are also described as looking like marble. Spider veins are caused by a backup of blood. These become nonfunctional, âdead-endâ veins.
While the fairy fly is the worldâs smallest insect, there a few runners up! For example, the feather wing beetle is only .25 millimeters long. Some scientists think these beetles may even be smaller than fairy flies, but for now, the fairy fly is considered by many to be the âsmallest insect!â.
Tunga penetrans is the smallest flea in the world, measuring 1 mm across. It is also known in Latin America as the nigua and bicho de pie (Spanish) or bicho de pÃ© (Portuguese), literally foot bug. Tunga penetrans is a member of the genus Tunga, which comprises 13 species.