Worldwide, living as an ectoparasite on humans but is also recorded from gibbons and New World monkeys.
Two morphological variants exist that were once thought to be separate species or subspecies. The form commonly referred to as “head lice” are restricted to the human scalp, while the form referred to as “body lice” are restricted to clothing and the human torso.
As a species, absolutely not endangered. However, populations restricted to isolated human tribes and non-human primates should be considered threatened.