What is an example of Parasitism?

This was just asked yesterday, so it would be in the archives, if you would check that out also.

Examples: Giardia lamblia: Dermacentor andersoni: Hookworms: Two species, Ancylostoma duodenale and Necator americanus infect humans: Pediculus humanus (head louse)

Here are six examples, with photos, of Parasitic Organisms (http://www.cbu.edu/~seisen/ExamplesOfParasitism.htm).

Look up each one for a definition, and you should be on your way to a comprehensive answer.