Definition of "blending"

Earless ghost swift moths become “invisible” to echolocating bats by forming mating clusters close (less than half a meter) above vegetation and effectively blending into the clutter of echoes that the bat receives from the leaves and stems around them.

2013 May-June, William E. Conner, “An Acoustic Arms Race”, in American Scientist, volume 101, number 3, pages 206–7