Similar to Sea Monkies, Tardigrades, and the Lung Fishes' ability to lie dormant, though the Graboids ability is far greater: the eggs can remain dormant for a time of 300 years. Since Graboid eggs can lie dormant for so long the shell can become fossilized in the process. The yolk however will remain concurrent. This allows the environment enough time to recover and provide enough food for the next generation of Graboids. For the eggs to awaken an outside heat source or sources need to be present as evidenced in Tremors 4: The Legend Begins when a hot spring was shown to have uncovered some eggs. It is not understood however how the Graboids of the previous two films were awakened though some fans think that the ones in Chiapas, Mexico were awakened by the drilling at the oil site due to