In the annals of animal urine marking, dogs are not the most impressive players. Hippopotami wave their tails as they spray urine, better to scatter it, sprinkler-like, in all directions. There are rhinoceroses who follow their high-powered urination onto bushes with destruction of the same bushes with horn and hoof—to ensure, presumably, that their urine is spread far and wide. Pity the owner whose dog is the first to discover the spreading-efficiency of high-powered, whirling-sprinkler urination.