Termites usually swarm throughout the warm season, with the first swarm occurring in spring. The combination of rain and warm temperatures in the spring months triggers the swarming every year.
In most cases, subterranean termites swarm during the day, even though there are some species such as the Formosan termites that swarm at night. To be apt for swarming, small termites first need to transform into nymphs with wing buds, and then into swarmers, which is a term that refers to sexually mature termites. Swarmers are dark colored and have two pairs of wings of the same size. The first swarm of termites is the most intense.