Head lice should not be considered as a medical or public health hazard. Head lice are not known to spread disease. Head lice can be an annoyance because their presence may cause itching and loss of sleep.

Their bites can make the scalp itchy and irritated, and scratching can lead to infection. Head lice are annoying, but they’re not dangerous and they don’t spread disease. They’re not a sign of poor hygiene — head lice need blood and they don’t care whether it’s from someone who’s clean or dirty.

There are many different species of bloodsucking fleas, lice, ticks and mites. Lice live on humans or in their clothing, while fleas are frequently found taking blood- meals on people and domestic animals.

They bite anywhere they are feeding on the head, but they are particularly fond of the back of the head and the area behind the ears because this is a warmer area of the scalp. The bites often appear as small reddish or pink bumps, sometimes with crusted blood. When scratched excessively, the bites can become infected.

Untreated head lice may degrade the scalp and affects it health and that of the hair. If the follicles become blocked, then hair loss may occur. It is hard to have well-conditioned hair if it is covered in head lice eggs, lice and bacteria.

Wash and dry bedding, clothing, and stuffed toys using hot water (130 F) and high heat. If the items can’t be washed, seal them in a plastic bag for 3 weeks. Dry cleaning also kills lice. Vacuum upholstered furniture and rugs.

Just like with mattresses, lice can only live on any bedding—whether it’s sheets, pillows, or comforters—for 1-2 days. Without a human scalp as a source for food (blood) for longer than 1-2 days, lice cannot survive.

Usually, pubic lice live on pubic hair in the genital area. If you look carefully, you may be able to see visible nits or crawling lice. Less commonly, they live on hair on other parts of your body. This may include legs, armpits, beard, eyebrows, eyelashes, or on your head.

Pubic lice are most commonly spread during sexual activity. You may also get pubic lice from infested sheets, blankets, towels or clothes.

You most likely cannot get crabs by sharing a toilet seat with someone who has them. The lice can’t live very long when they’re away from a human body. And their legs can’t hold onto a smooth surface like a toilet seat.