Termites are very secretive and will often enter a building through areas inaccessible to inspection, such as, via on-ground patios, cracks or expansion joints or around concrete slab flooring, particularly if the slab edge is obscured by pathways or garden beds.

This is an example of a mud-shelter tube that subterranean termites have built over a brick foundation wall to the flooring timbers in a sub-floor of a home.