Termite tubes coming up through paver stones

Jeff Hollis sent us this photo of subterannean termite tubes coming up between paver stones. Note that the tubes are constructed of the paver stone material. Sonora California, 2 May 2019.

Subterranean termite tubes built with paver stone. 2 May 2019, Sonora California
Subterranean termite tubes built with paver stone. 2 May 2019, Sonora California