Why do more fleas appear in summer? - briefly
Warm temperatures and increased humidity speed up flea life cycles, leading to faster egg hatching and higher adult numbers. Active outdoor hosts during these months also supply more blood meals, further boosting populations.
Why do more fleas appear in summer? - in detail
Flea populations surge during the warm months because temperature and humidity accelerate every stage of their development. Eggs hatch within a few days when ambient heat exceeds 20 °C; larvae mature faster under moist conditions, often reaching adulthood in less than two weeks. The shortened life cycle multiplies reproductive output, allowing several generations to appear within a single season.
Adult fleas require blood meals to reproduce. In summer, mammals and birds are more active outdoors, increasing the likelihood of contact with flea‑infested habitats such as grass, leaf litter, and animal bedding. Greater host movement spreads eggs and larvae over wider areas, creating new colonies.
Key environmental factors that favor infestation:
- Temperature: speeds metabolic processes, reduces developmental time.
- Relative humidity (70‑80 %): prevents desiccation of eggs and larvae.
- Organic debris: provides nourishment for larval stages and shelter from predators.
- Host density: higher numbers of animals concentrate blood sources, boosting egg production.
Control measures become less effective in hot weather because insecticides degrade more quickly under UV exposure, and frequent grooming by hosts may be reduced. Regular cleaning of animal shelters, maintaining low humidity, and applying heat‑stable treatments are essential to limit population growth during this period.