The mighty sperm whale is a multiple record-breaker. It is the largest of the toothed whales with some males reaching 20 metres in length. Its enormous box-like head with left-sided blow hole contains the biggest brain of any living animal. It is also the deepest diving mammal, reaching depths of 3,000 metres (nearly two miles) although the average dive is between 300 and 600 metres. These dives can last for a couple of hours before the whale has to come up for breath. A sperm whale’s ability to echolocate may aid in its hunt for giant squid and octopus. It makes clicks by blowing air that are among the loudest sounds made by any animal, possibly loud enough to stun prey. Sperm whales are found in all the world's oceans in tropical to sub-polar waters.

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