Demodox brevis and crab louse are two other bugs that are known to infest human hair other than head lice. There are other bugs that can be in human hair, but these are the two that prefer hair rather than exposed skin.
Crab louse is known to cling to the pubic hairs of humans but can also infest the hair on the head and even a person's eyelashes. Crab lice feed on human skin, and they case itching due to the irritation from the saliva of the lice. Demodex brevis are commonly referred to as eyelash mites or face mites. They attach to the end of the eyelash by the eyelid and live in the sebaceous glands of humans, where they reproduce.