When do ticks bite? - briefly
Ticks typically attach and begin feeding within 24–48 hours of contacting a host, most often during the warm months of spring and summer. Peak biting activity occurs in the early morning and late afternoon when hosts are less active.
When do ticks bite? - in detail
Ticks attach to hosts primarily during the warm months of spring and early summer, when ambient temperatures exceed 7 °C (45 °F) and relative humidity remains above 70 %. Under these conditions, ticks enter an active “questing” phase, climbing vegetation and extending their forelegs to detect carbon dioxide, heat, and movement from potential hosts.
Feeding activity varies with species and life stage:
- Larvae and nymphs: Most active in late spring and early summer; peak questing occurs between 0900 h and 1500 h when temperature and humidity are optimal.
- Adults: Peak activity shifts to midsummer through early autumn; questing peaks in the late afternoon and early evening, especially on warm, humid days.
Ticks are not limited to daylight hours. Many species, such as Ixodes scapularis and Dermacentor variabilis, will quest at night if temperature and moisture conditions are favorable. Conversely, activity declines sharply after sunset when humidity drops or temperatures fall below the threshold for metabolic function.
Environmental triggers:
- Temperature: Activity rises rapidly between 10–25 °C (50–77 °F); below 5 °C (41 °F) ticks become dormant.
- Humidity: Sustained relative humidity above 80 % prevents desiccation; low humidity forces ticks to retreat to leaf litter.
- Seasonal cues: Photoperiod and day length influence hormonal cycles that regulate questing behavior.
Host interaction:
- Ticks detect host presence through CO₂ exhalation, body heat, and vibrations. Once a host brushes against a questing tick, the tick clamps onto the skin and inserts its hypostome.
- Attachment time ranges from 24 hours for larvae to 48–72 hours for adult females before engorgement is complete.
- After engorgement, the tick drops off the host to molt or lay eggs, ending the feeding episode.
In summary, tick bites occur when environmental temperature and humidity support questing, predominantly from spring through early autumn, with specific daily peaks depending on species and developmental stage. Nighttime bites are possible under suitable conditions, while cold or dry periods suppress feeding activity.