Centipedes are predatory arthropods characterized by their elongated, segmented bodies and a single pair of legs on most segments. They are fast-moving carnivores, using modified front legs called forcipules to inject venom and subdue small invertebrate prey. Although centipedes exist year-round, their activity and visibility increase dramatically during specific times of the year. This seasonal surge, often called “centipede season,” is a direct response to favorable environmental conditions and their reproductive cycle.
Peak Activity and Environmental Triggers
The period of maximum centipede activity spans from late spring through early fall. This timeframe provides the warm and humid conditions these creatures require to thrive, optimizing their foraging and movement. Centipedes are highly susceptible to desiccation because they lack the waxy cuticle that helps insects retain water.
They seek out areas where the temperature is moderate, often between 68 and 75 degrees Fahrenheit, and where humidity levels are high. Humidity in the 70 to 80 percent range prevents their bodies from losing too much moisture. Consistent rainfall paired with summer heat creates an environment that encourages them to leave their sheltered resting spots.
Centipedes are most active at night, reflecting their nocturnal hunting behavior and their tendency to avoid direct sunlight, which causes dehydration. This allows them to take advantage of abundant food sources, such as insects and spiders, that flourish in the warm, humid climate.
Centipede Life Cycle and Reproduction
The seasonality of centipede sightings is closely tied to their reproduction, which occurs during the warmer, humid months. Mating and egg-laying usually happen in late spring and early summer. The female deposits her eggs in secluded, damp locations within the soil or leaf litter, sometimes guarding the clutch of up to 60 eggs until they hatch.
Centipedes are relatively long-lived, with some species surviving for six or more years. The development of the young is slow, involving a series of molts where they gradually increase the number of leg pairs. This timing means that the highest populations of smaller, newly matured centipedes become visible during the late summer and early fall, contributing to the perceived “season.”
Why Centipedes Seek Indoor Shelter
While warmer months mark peak outdoor activity, centipedes move indoors when outside conditions become unfavorable. Shifts in weather, such as the onset of cold in late fall or excessive drought, cause them to seek stable, sheltered environments. They are drawn to places that consistently provide the high moisture they require to survive.
Indoor areas like basements, crawl spaces, and laundry rooms are attractive because they mimic the centipede’s natural habitat of damp soil and leaf litter. These parts of a home maintain a higher, more consistent level of humidity and a moderate temperature. Furthermore, a centipede that moves inside is often seeking prey, as the presence of common household pests like silverfish, spiders, and roaches provides a ready food supply.