 Sperm whales usually dive between 300 to 800 metres ( 980 to 2 @,@ 620 ft ) , and sometimes 1 to 2 kilometres ( 3 @,@ 300 to 6 @,@ 600 ft ) , in search of food . Such dives can last more than an hour . They feed on several species , notably the giant squid , but also the colossal squid , octopuses , and fish like demersal rays , but their diet is mainly medium @-@ sized squid . Some prey may be taken accidentally while eating other items . Most of what is known about deep sea squid has been learned from specimens in captured sperm whale stomachs , although more recent studies analysed feces . One study , carried out around the Galápagos , found that squid from the genera Histioteuthis ( 62 % ) , <unk> ( 16 % ) , and <unk> ( 7 % ) weighing between 12 and 650 grams ( 0 @.@ 026 and 1 @.@ 433 lb ) were the most commonly taken . Battles between sperm whales and giant squid or colossal squid have never been observed by humans ; however , white scars are believed to be caused by the large squid . One study published in 2010 collected evidence that suggests that female sperm whales may collaborate when hunting Humboldt squid . Tagging studies have shown that sperm whales hunt upside down at the bottom of their deep dives . It is suggested that the whales can see the squid silhouetted above them against the dim surface light . 
