Archaea live in some of the most extreme environments on the planet. They are able to survive in temperatures above 100 ° C, in the depths of the sea at high pressures, where they produce methane. Others live in hot springs, or in the Arctic and Antarctic oceans, which remain frozen for most of the year, or in extremely alkaline or acidic waters. Were found in the digestive tract of cows and termites. They live in the anoxic muds of marshes and thrive in petroleum deposits at depth. They were even found in car batteries!