Pygmy sperm whale significant concentration of magnetite crystals, which suggests that "K. breviceps" can navigate by magnetoreception. Studies have also shown that compared to the sperm whale, the pygmy sperm whale brain has significantly fewer neurons, which may be connected to a decreased complexity in social interaction and group-based living. Like all toothed whales, the pygmy sperm whale hunts prey by echolocation. Sound produced for echolocation by many odontocetes come in the form of high frequency clicks. The frequencies it uses are mostly ultrasonic, peaking around 125 kHz. The clicks from their echolocation has been recorded to last an average of 600 microseconds.
Blue whale of its life, a blue whale calf drinks approximately of milk every day. Blue whale calves gain weight quickly, as much as every 24 hours. Even at birth, they weigh up to —the same as a fully grown hippopotamus. Blue whales have proportionally small brains, only about , about 0.007% of its body weight, although with a highly convoluted cerebral cortex. The blue whale penis is the largest penis of any living organism and also set the Guinness World Record as the longest of any animal's. The reported average length varies but is usually mentioned to have an average length