When it begins to rain in California, termites emerge from the ground and take flight on wings that will fall off in hours. Hopefully, for them anyway, they've found a mate and are ready to build a new underground colony and take their thrones as king and queen. From KQED Science's Deep Look:
Once a pair of flying termites have hooked up, they lose their wings, dig underground, mate and lay thousands of eggs. They will be the king and queen of their colony. The worker termites they make will then leave the nest to forage for sources of cellulose, like a dead tree, or wood in a house. When they return to the nest, these workers will feed the colony's king and queen, as well as the young termites[…]
If you see termites flying out inside your house, they could be a sign of infestation. But the more common signs of a subterranean termite infestation are tubes made from earth that worker termites build at the bottom of your house connecting wooden structures to the soil. Termites build these so-called shelter tubes from mud, saliva and even bits of wood or drywall. The insects desiccate easily and need these covered shelter tubes to stay moist.