[basicplus2]

Termites only fly when a colony has reached a limit on number, and pairs fly off to start new colonies.

unless they start a new colony inside the barrier, the barrier is still effective.

[markdown]

The barrier is only affective against burrowing, but termites don't start new colonies by burrowing. They swarm (usually once annually)... fly off and build new colonies. If only the method described here actually worked, we'd save billions of dollars a year in damage.