Lobsters have two urinary bladders, located on either side of the head. Lobsters use scents to communicate what and where they are, and those scents are in the urine. They project long plumes of urine 1–2 meters (3 ft 3 in–6 ft 7 in) in front of them, and do so when they detect a rival or a potential mate in the area.
American lobster - Wikipedia, the free encyclopedia
When lobsters want to attract a mate, the pee out of their heads.
Source: Wikipedia