The get on the worker termites without them even knowing it, and it is passed from termite to termite, since they are a very social colony, and that eventually gets back to the queen of the colony. You have to kill the queen to kill the colony, but she's not the termite invading your house. Because they are so social, though, they rub all over each other, and the pesticide gets carried back to the colony and is very effective. These aren't the pesticides you can buy at home depot, though. They aren't available like ant and roach spray. So it is one that you do need to shop around for the expert that is licensed to apply it.