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.
Right whale whales have a distinctive wide V-shaped blow, caused by the widely spaced blowholes on the top of the head. The blow rises above the surface. Right whales have between 200 and 300 baleen plates on each side of their mouths. These are narrow and approximately long, and are covered in very thin hairs. The plates enable the whale to filter feed. The penis on a right whale can be up to – the testes, at up to in length, in diameter, and weighing up to 525 kg (1157 lbs), are also by far the largest of any animal on Earth.