ABSTRACT
SincelifeonEarthbegan,membersoftheanimalkingdomhavesought refugeunderground.Recognisingthepotentialofsoilasaprotectivemedium,mantoohasbuiltundergroundstructurestoaffordshelterfromhis enemy.Soil'squalityofperformanceinthisrolederivesfromitsinertia,its abilitytodiffuseload,itscapacitytodissipateenergyinplasticdeformation and,ofcourse,itsobscurationofthetarget.
