Sea turtles are one of the oldest creatures on earth. There are seven species of sea turtles, which have been around for 110 million years, since the time of the dinosaurs. They live in almost every ocean basin in the world. Their diet consists of jellyfish, seaweed, crabs, shrimp, sponges, snails, algae and mollusks, however some species eat mostly sponges. The sea turtle’s shell is made for swimming and unlike other turtles, they cannot retract their head and legs into it. Dermochelyidae (leatherback sea turtles) and Cheloniidae (green turtles, flatback sea turtles, loggerhead sea turtles, hawksbills, and ridleys) all spend most of their lives in the water, and only appear on the shore to lay their eggs. The largest turtle, the leatherback sea turtle, can weigh up to 2,000 pounds. Most sea turtles are carnivorous and prefer warm, coastal marine environments. They migrate between foraging and nesting grounds, and usually to find warmer temperatures. When baby sea turtles hatch, their instinct is to crawl towards the water because even though it is dark, the light above the water is brighter than the light above the land. They have to hatch at night because it is less likely for them to be eaten. When female loggerhead sea turtles hatch, they remember the beach on which they hatched and can navigate back to it as adults to lay eggs of their own. They do this a few times per season every 2 to 5 years. Baby sea turtles can be eaten by crabs, birds, or raccoons on their way to the water, or by seabirds or fish if they make it to the ocean. Usually only one of a thousand sea turtles will make it to adulthood. When they get into the water, they swim for about a day to get to their destination. Then their location is unknown for about ten years, before they return to a coastal area to continue maturing and growing. Due to global warming, sea turtles have become endangered. The climate change has been detrimental to sea turtles because it determines the gender of their babies. Higher temperatures cause sea turtles to have mostly female babies. Sea turtles are also endangered because of humans killing them for their eggs, meat, skin and shells. Ocean pollution and coastal development are taking over their nesting and feeding sites, making it harder for them to find places to hatch their eggs.