Body lice are small, flat, wingless insects about 2.3 to 3.6 millimeters long, roughly the size of a sesame seed. They’re grayish-white or tan when unfed, turning darker and more reddish-brown after a blood meal. Unlike head lice, which live on the scalp, body lice spend most of their time hiding in clothing and only move to the skin to feed.
Size, Shape, and Color
An adult body louse has an elongated, oval body with six legs, each tipped with a small claw used for gripping fabric fibers. They look very similar to head lice but are slightly larger. To the naked eye, they resemble a tiny pale grain of rice with legs. Their color shifts depending on when they last fed: a louse that just took a blood meal will appear noticeably darker, sometimes reddish or rust-colored, because you can see the blood through its semi-translucent body.
You’re unlikely to spot body lice on your skin unless you catch them mid-feed. They retreat to clothing almost immediately after eating, which makes the insects harder to find than head lice.
What the Eggs Look Like
Body lice eggs, called nits, are tiny oval capsules about 0.8 millimeters long, yellowish-white, and cemented firmly to fabric fibers. They’re most often found along the inner seams of clothing, especially around the waist, underarms, and neckline where fabric sits close to the body and stays warm. The warmth from your skin is what allows the eggs to develop. Eggs take 5 to 7 days to hatch.
If you’re checking clothing, look closely at the seams and folds rather than flat surfaces. The eggs can be hard to distinguish from lint at a glance, but they won’t brush off easily the way lint does. They’re glued in place and resist casual removal.
Nymphs vs. Adults
When an egg hatches, the emerging nymph looks like a smaller, paler version of the adult. Nymphs go through three molts over 16 to 18 days before reaching full adult size. During this period, they already feed on blood and stay in clothing between meals. Because nymphs are smaller and lighter in color, they’re even harder to see than adults. By the time they reach maturity, body lice live another 30 to 40 days total.
Where to Look for Them
The CDC recommends checking the seams of clothing for both crawling lice and eggs as the primary way to confirm an infestation. Body lice prefer areas where fabric folds create dark, tight spaces close to the skin. The waistband, inner seams of shirts near the armpits, and collars are the most common hiding spots. Turning clothing inside out under good lighting gives you the best chance of spotting them.
On the body itself, you’re more likely to see evidence of bites than the lice themselves. Bites typically appear as small red spots or raised bumps, often in clusters around the waist, shoulders, and upper back, wherever clothing fits snugly. Intense itching is the hallmark symptom. In long-standing infestations, the skin in heavily bitten areas can thicken and darken, a condition sometimes called vagabond’s disease.
How to Tell Them Apart From Other Pests
Body lice are sometimes confused with bed bugs, fleas, or head lice. A few key differences help with identification:
- Bed bugs are broader and rounder, about the size of an apple seed, and hide in mattresses and furniture rather than clothing.
- Fleas are darker brown, laterally compressed (tall and narrow rather than flat), and jump. Body lice do not jump or fly.
- Head lice look nearly identical but are slightly smaller and live exclusively on the scalp and hair. If you’re finding lice in clothing seams rather than on hair shafts, they’re body lice.
Getting Rid of Body Lice
Body lice are unusual among lice species because the primary treatment doesn’t involve medicated shampoos or topical products. Since the insects live in clothing, not on the body, the most effective step is washing all infested clothing and bedding in hot water (at least 130°F or 54°C) and machine drying on high heat for at least 30 minutes. Items that can’t be washed should be sealed in a plastic bag for two weeks, long enough for any remaining lice and eggs to die without a blood meal.
Regular bathing and access to clean clothing resolve most infestations without any additional treatment. Body lice infestations are strongly associated with situations where people can’t change or wash clothes regularly, such as homelessness or displacement. When those conditions are addressed, the lice typically disappear on their own.