You get crabs (pubic lice, Pthirus pubis) mainly through skin-to-skin sexual contact, when these tiny blood-feeding insects crawl from one person's coarse pubic hair to another's. Less often they pass through shared clothing or bedding, and only very rarely from a toilet seat. You can't catch them from pets or casual contact.
with the right treatment
testing, not symptoms, decides
| Item | Value |
|---|---|
| Curable? | yes — with the right treatment |
| Tested by | exam + lab |
| Often | no symptoms |
| If you may have it | get tested — testing, not symptoms, decides |
How crabs are transmitted
Pubic lice are insects, not a virus or bacteria, and they live their whole lives clinging to coarse body hair where they feed on blood several times a day CDC DPDx. Because they can't fly or jump and move slowly, they need close, sustained contact to get from one host to another. That's why the overwhelming route is sexual contact.
Sexual and intimate skin-to-skin contact
During sex, the pubic regions press together long enough for adult lice to walk from one person's hair to another's CDC. This is the main way crabs spread, and it can happen even when there's no penetration — close genital-to-genital or hair-to-hair contact is enough. Condoms don't fully prevent it, since lice live on the hair around the genitals rather than only on areas a condom covers.
Shared clothing and bedding
Occasionally lice or their eggs transfer through shared items that touch the body's hairy areas — underwear, towels, or bedding used by an infested person CDC. This is far less common than sexual spread, partly because adult lice die within a day or two once they're off a human and away from a blood meal. Sharing a bed or towel with someone who has an active infestation carries some real (if low) risk; brushing past someone's coat on a hook does not.
Toilet seats — technically possible, practically negligible
A toilet seat is the classic worry, and the honest answer is that transmission this way is very rare CDC STI Treatment Guidelines. Lice are built to grip hair, not smooth surfaces, and they don't survive long away from the body. They wouldn't normally fall onto a seat and then climb onto the next person, so a public restroom isn't where people pick these up.
How you do NOT get crabs
If you've been replaying every place you sat or every hand you shook, here's where you can stop worrying. Crabs don't spread through the everyday routes people fear most:
- Toilet seats and other smooth surfaces — lice can't hold on to them and die quickly off the body.
- Shaking hands, hugging, or casual contact — there's no hair-to-hair transfer in these.
- Saliva, kissing, or sharing drinks — pubic lice live in coarse body hair, not the mouth, so saliva alone doesn't pass them.
- Swimming pools and hot tubs — chlorinated water doesn't carry lice between people.
- Pets and animals — dogs, cats, and other animals neither get nor spread human pubic lice.
- A towel someone touched briefly or a bench you sat on — meaningful risk requires close contact with an infested person's hairy skin or recently used personal items.
The takeaway: crabs are an intimacy-and-shared-bedding problem, not a public-surface problem. Worrying about a restroom is misplaced; the conversation worth having is with recent sexual partners.
Who's at higher risk
Anyone who's sexually active can get pubic lice, but a few patterns raise the odds. People with new or multiple sexual partners encounter more potential sources of exposure. Sharing a bed, towels, or clothing with someone who has an active, untreated infestation also increases risk. Because lice prefer coarse hair, people with more pubic, perianal, or body hair give the insects more territory to settle into.
None of this reflects on hygiene or character. Pubic lice infest clean and unwashed people alike — they only care about access to hair and blood, not how often you shower.
Reducing the risk
Because pubic lice ride on hair around the genitals, prevention is partly about contact and partly about not sharing the items lice can hitch onto:
- Avoid sexual or close hair-to-hair contact with anyone who has an untreated infestation until they've finished treatment.
- Don't share underwear, towels, bedding, or razors with someone who may be infested.
- Condoms used every time lower risk for the sexually transmitted infections, and routine testing catches the ones that have no symptoms — though condoms don't fully block lice, the broader habit of safer sex and regular checkups protects you across the board.
- If you find lice, treat yourself and decontaminate clothing and bedding at the same time so you don't reinfest.
If you're trying to clear an active case, see our guide on how to get rid of crabs at home for the step-by-step, including the laundering and re-treatment timing that trips people up.
If you think you've been exposed
If a recent partner tells you they have crabs, check yourself for itching and tiny lice or nits, and read up on when to test after exposure for the other infections that often travel alongside them — a crabs diagnosis is a good prompt to get tested for the full STI panel.
When to see a clinician
You can often confirm pubic lice yourself by spotting the insects or their eggs in coarse hair, but see a clinician if you're unsure, if over-the-counter treatment doesn't work, or if you notice signs of skin infection from scratching (redness, oozing, or worsening soreness). Children with lice in the eyelashes or other body hair should be evaluated, since that can raise other questions. If you're not sure what you're seeing, our overview of crabs symptoms walks through the itching, the rust-colored specks, and the live lice so you know what to look for — and lice can settle in crabs in eyebrows, eyelashes & other body hair, which needs gentler handling than the genital area.
One honest note: a diagnosis here is common and entirely treatable. Clinics handle it daily, and it says nothing about you as a person — it's an insect, and it goes away with treatment.