Sea turtles swim thousands of kilometers to the seaside where they were born during the spawning season. When a sea turtle gets home, it digs a pit in the sequestered sand and lays 50 to 200 eggs as big as ping pong balls. Afterwards, it immediately covers the pit with sand to protect the eggs from predators and to maintain the proper temperature for hatching.
That is all the mother turtle does. Hatching and surviving are up to the young. Two months after the mother leaves, the young that have broken out of the eggs work together to escape the dark and hard sand pit. The cubs at the top of the pit break through the ceiling, those in the middle break down the walls, and those at the bottom step on the sand falling from above. For three to seven days, the cubs break through thick sand together and come into the outside world at the same time.
A scholar, as an experiment, buried eggs separately and found that their survival rate was only 27%. It seems that the sea turtles instinctively know from birth that they can live only when they come together. That is probably the reason why the mother turtle can leave her young.