When they surface, sperm whales typically blow 20-70 times before redescending. They produce a visible spout made by the condensation of the moisture combined with a mucous foam from the sinuses. Giant sperm whales typically swim at speeds no faster than 10 km per hour, but when disturbed they can attain speeds of 30 km per hour. Giant sperm whales are highly gregarious, polygamous and group themselves roughly by age and sex in group sizes of 100 or more individuals. Loose family groups of about 30 individuals, however, are more common.
Older males are usually solitary except during the breeding season.
During the breeding season, breeding schools composed of 1-5 large males and a mixed group of females and males of various ages form. Their voices are quite loud and can be heard many kilometers away with underwater listening devices. Each whale also emits a stereotyped, repetitive sequence of 3-40 or more clicks when it meets another whale. Because they are so well-adapted for deep water swimming, they are in real danger of stranding when they move inshore. Physeter catodon has also been a target of commercial whaling in years gone by, notably in areas around the Gulf of Mexico.