How long does a tick live after biting a human? - briefly
A tick stays attached to a human host for about three to five days, occasionally up to a week, to complete its blood meal. After dropping off, the adult can survive several months in the environment before dying.
How long does a tick live after biting a human? - in detail
Ticks remain alive only for a limited period after they have attached to a person and completed a blood meal. Once engorged, most species detach within 24–48 hours. After dropping off, the tick’s life expectancy depends on its developmental stage and environmental conditions.
- Larvae and nymphs: After feeding, these stages usually seek a sheltered site to molt. In favorable humidity and temperature, they can survive a few weeks to several months before undergoing ecdysis. If conditions are harsh, mortality occurs within days.
- Adults: Female adults require a single large meal to develop eggs. After detachment, a gravid female can live for 1–2 weeks while laying eggs, after which she dies. Unfed adult males may persist for several months, but once they have fed, survival declines sharply, typically not exceeding a fortnight.
Key factors influencing post‑feeding survival:
- Humidity: Ticks are prone to desiccation; relative humidity above 80 % markedly extends their lifespan.
- Temperature: Moderate temperatures (10–25 °C) support longer survival; extreme heat accelerates death.
- Host availability: Access to another host can prolong life, but after a human bite most ticks do not re‑attach.
- Species: Ixodes scapularis (black‑legged tick) often survives longer post‑feeding than Dermacentor variabilis (American dog tick) under identical conditions.
Overall, a tick that has fed on a human will usually die within two weeks if it does not find a suitable environment for molting or egg laying. Survival beyond this window is rare and typically limited to unfed adults that have not yet completed their reproductive cycle.