It's not just dogs and cats that make statements with their urine.
Crustaceans do it too.
Pheromones carried in lobster urine, for example, appear to allow males of the species to maintain dominance and to attract mates. This is the very question Thomas Breithaupt of the Konstanz University, Germany and colleagues have been trying to answer by catheterising lobsters. They then carried out a second experiment on six male and six female lobsters. There is no evidence that lobsters use their urine as a 'chemical weapon'. After all it is secreted in bursts rather than continuously and the existence of a potential pheromone gland behind the sphincter muscles of the nephropores indicates that its composition can be manipulated.