If humans had better noses these taggers would simply have urinated against those buildings to mark their territory but since this does not leave a recognisable

If humans had better noses these taggers would simply have urinated against those buildings to mark their territory but since this does not leave a recognisable mark (for humans) they use spray paint instead of urine. The purpose, effect and level of artistry are comparable to that of a dog lifting its leg next to a lamppost.