Bed bugs or lice: how to tell? - briefly
Bed bugs are small, reddish‑brown insects that hide in mattress seams and leave tiny, dark, oval spots, often biting without immediate itching. Lice are elongated, wingless parasites that attach to hair shafts, causing an itchy scalp and visible nits near the roots.
Bed bugs or lice: how to tell? - in detail
Distinguishing between Cimex infestations and Pediculus capitis requires careful observation of size, coloration, habitat, feeding behavior, and signs left on the host or surroundings.
Bed bugs are oval, flat, and reddish‑brown. Adults measure 4–5 mm in length, similar to an apple seed. They hide in seams of mattresses, box springs, bed frames, and furniture cracks during daylight. After feeding on exposed skin, they retreat and may be found in the same hiding places within a few hours. Their bites appear as a line or cluster of small, raised, erythematous spots, often accompanied by itching. In the environment, one may notice tiny dark spots (fecal excrement) on bedding, shed exoskeletons, or a sweet, musty odor.
Head lice are elongated, grayish‑white insects about 2–4 mm long. They cling to hair shafts, primarily on the scalp, and lay eggs (nits) firmly attached to each strand near the scalp. Nits are oval, tan, and difficult to remove without a fine‑toothed comb. Lice feed several times a day, causing intense itching and the appearance of small, red papules on the neck, shoulders, and behind the ears. No excrement or odor is typical, and infestations are confined to the hair and scalp, not to bedding.
Key visual cues for identification:
- Body shape: Bed bugs – flattened, oval; lice – elongated, cigar‑shaped.
- Size: Bed bugs larger (4–5 mm); lice smaller (2–4 mm).
- Color: Bed bugs reddish‑brown; lice grayish‑white.
- Location: Bed bugs in mattress seams, furniture; lice on hair shafts.
- Egg attachment: Bed bug eggs loosely attached to surfaces; lice nits glued to hair.
- Bite pattern: Bed bug bites in rows or clusters; lice bites scattered on scalp and neck.
- Environmental signs: Bed bugs leave fecal spots and shed skins; lice leave only nits and occasional dead insects.
Effective diagnosis combines visual inspection of the host’s skin and hair with examination of sleeping areas. Use a magnifying lens to confirm morphology, and employ a fine‑toothed comb to detect nits on hair. Absence of bedding contamination and presence of firmly attached nits strongly indicate a lice problem, whereas detection of live insects or excrement in the mattress points to a bed‑bug infestation.