"So, naturalists observe, a flea has smaller fleas that on him prey; and these have smaller still to bite ’em; and so proceed ad infinitum."
- Jonathan Swift
January 22, 2010
January 22 - Pediculus humanus capitis
What do parents dread their children bringing home from school more than a bad report card? Pediculus humanus capitis, better known as head lice. These wingless insects, also called sucking lice, have parasitized humans for thousands of years and are now are common worldwide, infesting millions of school children every year. Head lice are entirely dependent on their hosts for their survival (there are no free-living stages), are found on the head and attach their eggs to the base of hair shafts. These parasites are surprisingly nimble, moving quickly among the hairs and can transfer quickly to a new host should the opportunity present itself. Head lice reproduce rapidly and treatment can be expensive and time consuming. Many common colloquialisms resulting from human parasitism of lice include “nit-picking”, “going over with a fine-toothed comb”, “nitwit”, and “lousy”.
Contribution by Jessica Light.