Build a utopia and hatch prehistoric critters with Underwater City Triopolis! Triops are 'living fossils' which are identical to their prehistoric kin from millions of years ago. They can survive by suspended animation which helps them stop their biological clock. Children will lay triop eggs in the Hatchery. The Triops will begin to hatch within 2-3 days! The Tripolis provides the ideal opportunity to study the behaviors of a fast-growing creature that hasn't changed in a million years.