Snakes evacuate both feces and urine through the cloaca, which is also the entry point for the reproductive tract. The cloaca has three chambers: the coprodeum, which holds feces; the urodeum, which receives the urogenital ducts; and the producteum, a mixing chamber for urine and feces.
All snakes have a cloaca, as do all other reptiles. Other animals that have cloacas are sharks, rays, lobe-finned fishes, birds, amphibians and monotreme mammals. Placental mammals usually have separate orifices for the digestive, urinary and reproductive tracts, but human beings are sometimes born with a complex malformation called a persistent cloaca in which the anal, urinary and reproductive tracts are fused.