How can lice be caught? - briefly
A fine‑toothed comb applied to wet hair, followed by inspection on a white towel or plastic sheet, captures both lice and nits. Light‑based traps or adhesive pads can also be used to attract and retain the insects.
How can lice be caught? - in detail
Capturing lice requires a systematic approach that combines visual detection, mechanical removal, and, when necessary, specialized trapping devices.
A thorough visual inspection begins with a well‑lit environment and, if available, a magnifying lens or handheld loupe at 10‑20× magnification. Examine the scalp, behind the ears, and at the nape of the neck. Look for live insects, which appear as small, gray‑brown bodies approximately 2–4 mm long, and for nits attached firmly to hair shafts within 1 cm of the scalp.
Mechanical removal uses a fine‑toothed nit comb. Wet the hair with a conditioner to reduce slip, then run the comb from the roots to the tips in a single, deliberate stroke. After each pass, wipe the comb on a white surface to confirm capture. Repeat the process on all sections of the head, then repeat the entire routine after 7–10 days to address newly hatched lice.
When visual methods are insufficient, adhesive tape or sticky slide traps can collect specimens. Press a piece of clear medical tape against the scalp for several seconds; lift the tape and examine it under magnification. Sticky slides placed near the hairline for 15–30 minutes attract mobile lice that crawl onto the adhesive surface.
For research or large‑scale screening, pheromone‑based traps provide a passive capture method. Synthetic head‑lice aggregation pheromones, combined with a low‑volatile solvent, are applied to a gauze pad inside a vented container. The container is positioned near the hairline for 4–6 hours. Captured insects are retrieved by removing the gauze and placing it in a labeled vial with ethanol for preservation.
Carbon‑dioxide traps exploit the insects’ attraction to exhaled breath. A sealed container holds a small source of dry ice or a CO₂ cartridge, with a mesh screen allowing lice to enter but not exit. The trap is placed on the scalp for 30 minutes, after which the screen is examined and any insects are collected with forceps.
In summary, effective lice capture employs:
- Direct scalp examination with magnification
- Nit combing on wet hair, repeated after a week
- Adhesive tape or sticky slides for immediate collection
- Pheromone‑laden gauze traps for passive sampling
- CO₂‑based containers for attraction and containment
Each method serves a specific purpose: detection, removal, or specimen preservation. Selecting the appropriate technique depends on the intended outcome—whether personal treatment, clinical diagnosis, or entomological study.