1) Wood powder near wooden structures or furniture: If you have been noticing fine, sawdust-like wood powder around your house, chances are your house might be infested by wood-boring insects such as wood-boring beetles or drywood termites. 2) Mud tubes: Mud tubes are tunnels constructed by subterranean termites to provide a sheltered pathway when they venture out of their nests to forage for food. 3) Flying termites: Alates or swarmers are termites with wings. Termite swarms are one of the most obvious signs of termite infestations.