These are termites, and individuals with wings (which can be called "swarmers") are reproductive members of the colony, whose only function is to mate and disperse to start their own colonies. (The females, anyway...the winged males die fairly soon after mating.) Reproductive individuals don't contribute to colony maintenance (chewing tunnels in wood, for example) but if they are appearing in the home then it might indicate a termite colony is nesting inside wood in the home and has been for some time. You don't need to panic since significant termite damage isn't sudden, but we recommend consulting a pest control professional who can help determine where damage might be occurring and who can apply any appropriate treatments to eliminate the colony and prevent others from establishing.

Miri