Swarming usually occurs in the evening hours following a warm, rainy day in the late spring or early summer. A single colony of Formosan termites may release over 70,000 swarmers.

What time of year do Formosan termites swarm?

Eastern subterranean Termites swarm late March through early May. Formosan subterranean Termites swarm late May through June.

What causes Formosan termites to swarm?

If a Formosan termite colony has a lack of food or water, a swarm may be triggered. ... When Formosan termites are stressed, either in the soil or inside wood, they will leave their colony and seek food and water somewhere else. These termites depend on moisture, so they can't go long without some type of water.