I wonder how many members hav ever seen a nit. For a guess it would take twenty of them to equal volume of a single rice kernel,and they are almost pale skin color. They used to be quite common, but I think are now rather uncommon.
It is a head louse egg, and it has the most amazing tight
tubular attachement to he hair, at an angle of almost 45 degrees that makes them difficult to remove. It used to be necessary to have a comb with very fine teeth that the nits could not be passed through, but would be drawn all the way to the end of the hair if the attachment did not break.
I found many sites for shampoos that ought to be better than the one I used to prescribe. And combs too.
So today nitpickers have trouble finding anything more meaningful to do than make a big fuss about other people's
tiny errors.
For pictures, scroll down 1/2 at:
http://www.headlice.org/faq/lousology.htm