There are actually a number of animals that do that. Bears will scratch the tree trunks with their claws to leave a visual and olfactory marker that they peed or pooped. I was actually watching my dog, Dune, do this yesterday. He left six-foot-long scratches on the ground probably 8 feet into the street. What they’re leaving is a very long visual marker, plus an olfactory one. Scratching leaves the scent from their paws and by scratching the dirt, it leaves a very fresh odour and a line, kind of like an arrow: follow this line of scratched dirt and at the end of it, yes, urine.