Why do chickens have lice? - briefly
Chickens are infested by lice because these ectoparasites exploit the bird’s feathers and skin for food and shelter, especially in warm, crowded, or unhygienic environments. The parasites persist where birds have close contact and insufficient grooming or preventive treatment.
Why do chickens have lice? - in detail
Chickens become hosts for lice because the insects find the birds’ feathers and skin suitable for feeding, reproduction, and shelter. Lice are obligate ectoparasites; they cannot survive without a living bird. The primary factors that promote infestation include:
- Close confinement – High stocking densities limit the ability of birds to groom and increase contact between individuals, facilitating transfer of parasites.
- Poor sanitation – Accumulated manure, dust, and organic debris create a humid microenvironment that supports egg hatching and nymph development.
- Warm, moist conditions – Temperatures between 25 °C and 30 °C and relative humidity above 60 % accelerate the life cycle, which can be completed in 10–14 days.
- Inadequate biosecurity – Introduction of new birds, equipment, or personnel without proper quarantine or disinfection allows external lice populations to enter a flock.
- Compromised immunity – Nutritional deficiencies, stress, or concurrent diseases reduce the bird’s ability to resist parasite colonization.
The life cycle of poultry lice consists of egg, three nymphal stages, and adult. Females lay 2–4 eggs per day, attaching them to feather shafts. Eggs hatch within 5–7 days, and each successive nymph molts after 2–3 days. Adults live 2–4 weeks, during which they feed on blood, skin scales, and feather debris, causing irritation, feather loss, and reduced weight gain.
Transmission occurs primarily through direct contact between birds. Secondary routes include contaminated equipment, housing structures, and litter. Lice do not jump or fly; they crawl, making thorough cleaning of the environment essential for control.
Effective management combines preventive and therapeutic measures:
- Environmental sanitation – Regular removal of manure, thorough drying of housing, and periodic replacement of litter reduce habitat suitability.
- Stocking density reduction – Allowing sufficient space per bird minimizes physical contact and improves air circulation.
- Routine health monitoring – Visual inspection of plumage and skin for nits or adult lice enables early detection.
- Chemical control – Application of approved insecticidal sprays or powders (e.g., pyrethroids, organophosphates) according to label instructions; rotation of active ingredients prevents resistance.
- Biological options – Use of entomopathogenic fungi or predatory mites where approved, offering non‑chemical alternatives.
- Quarantine protocols – Isolating new arrivals for at least 14 days and treating any detected parasites before integration.
Understanding the ecological requirements of lice and implementing rigorous husbandry practices remain the cornerstone of preventing infestations in poultry operations.