Lobsters have a most usual way of communicating: They pee in each other’s faces.
When lobsters urinate they are also releasing pheromones (or chemical smells) at the same time. The glands are connected to the urinary tract, so they can produce pheromones and then introduce them into the urine stream. American lobsters (Homarus americanus) release this urine from nephropores at the base of their large antennae. That’s right, lobsters pee out of their heads. Since it faces the opening of the cave, peeing out of their heads is the most direct route for the urine to reach the water around them.