|Abstract||In the XVIIth century, physicians still considered that lice are issued from the body excretions by a "spontaneous generation" phonomenon. It does not disturb the patients who continue to treat themselves by delousing. This is painted very often in Dutch paintings from this century, especially in "genre painting", which is specific of Holland. Delousing is not only anecdotical, but has a deeper meaning has, it is symbolic of the good care that women must take of their children, but also a symbol of human sins and bad behaviour. Through the paintings of several Dutch painters, lice can therefore give an idea of the XVIIth century Dutch society.