Termites are social insects, often identified by their destructive impact on wooden structures. Homeowners frequently observe the sudden appearance of winged termites, called swarmers, at certain times of day or night. This phenomenon sparks questions about why these insects emerge and what it signifies for a property. Understanding these behaviors and environmental triggers offers insight into the complex life cycle and dispersal strategies of these pests.
Understanding Termite Activity
The phrase “termites coming out at night” refers to the winged, reproductive members of a colony, known as alates or swarmers. The majority of a termite colony, composed of worker and soldier castes, remains concealed within their subterranean nests, wood galleries, or mud tubes. Worker termites tirelessly forage for cellulose, feed other colony members, and maintain the nest infrastructure, while soldiers defend the colony from threats. These non-reproductive castes rarely venture into the open.
The visible emergence, or swarming, represents the dispersal flight of alates, whose primary purpose is to reproduce and establish new colonies. Swarming patterns vary by termite species and geographic location. Subterranean termites typically swarm during the daytime, often in spring and after rainfall. Conversely, drywood termites are known for swarming at night, usually in late summer or early fall. This distinction highlights that while many species swarm, nocturnal emergence is characteristic of certain types, not all.
Environmental Factors Influencing Emergence
The precise timing of alate emergence is finely tuned to environmental conditions that enhance their prospects for survival and successful colony establishment. Light is a notable factor, as many termite alates display a positive phototaxis, meaning they are drawn to light sources. This attraction can guide them in their search for new territories. Darkness provides an advantage by reducing their exposure to visual predators like birds, lizards, and spiders, which pose a threat during daytime flights. Nocturnal flights also minimize the risk of desiccation, as the cooler night air typically holds more moisture, protecting their bodies from drying out.
Temperature and humidity levels are also environmental cues that trigger swarming events. Warm temperatures, often ranging from 70 to 80 degrees Fahrenheit (21-27 degrees Celsius), combined with high humidity, create optimal atmospheric conditions for alate flight and new colony establishment. Humid conditions, frequently occurring after rainfall, are essential for preventing the alates’ exoskeletons from dehydrating during flight. Moist soil, a direct benefit of recent precipitation, offers an ideal substrate for newly mated pairs to burrow and initiate their new nest, providing moisture and shelter for the founding queen and king.
The Reproductive Imperative
Termite swarming represents the biological process for colony reproduction and species dispersal. A mature termite colony, which can take several years to develop, produces winged alates to expand. These alates embark on a dispersal flight to locate a mate and initiate a new colony, extending the species’ reach.
Nocturnal flights offer evolutionary advantages, particularly for drywood termite species. Nighttime diminishes the threat from diurnal predators, such as birds and insects, allowing more alates to survive the flight phase. Once they land, male and female alates shed their wings, signaling their transition from flight to founding. They then seek a secluded, moist location to excavate a new nest. This nocturnal timing often aligns with finding moist soil, especially after rainfall, which is essential for successful burrowing and survival of the royal pair. Despite the large numbers that swarm, only a small percentage establish viable new colonies, yet this strategy is effective for population expansion.