Narwhals usually organize outside of the summer in groups of about five to ten or 20 members. Groups might be 'nurseries' with only females and young, or may only include post-dispersal juveniles or adult males ('bulls'), but combined populations may appear at any time of year. Numerous groups come together during the summer, forming larger clusters with 500 to over 1000 members.
A bull narwhal might indeed squeeze its tusk with another bull, a demonstration referred to as "tusking" and considered to establish hierarchies of social dominance. Similarly, this response may express tusk use as a cognitive and communication organ to express sensed water chemistry information in tusk microchannels.
They move closer to coastlines in summer months, mostly in 10–100 pods. They migrate offshore in winter, deeper waters under dense pack ice, surfacing in thin fissures or leads in the sea ice. These leads open into channels as spring comes, and the narwhals come back to the shoreline bays. Winter feeding contributes to a much larger portion of narwhal energy expenditure compared to summer.
When swimming, narwhals are estimated to swim up to 160 km a day.
Which averages approximately 6.5 km per hour. Narwhals have a reasonably small but highly advanced diet. Their diet consists mainly of Greenland halibut, arctic and Arctic cod, cuttlefish, shrimp, and arm hook squid.
Additional things found in the stomach included capelin, skate eggs, and occasionally rocks, which were unintentionally swallowed while the whales were feeding at the base. Because of the absence of well-developed dentition in the mouth, it is assumed that narwhals feed by swimming towards a prey once it is within close proximity and then swallow it into the mouth with significant force. The beaked whales, which have similarly diminished dentition, are believed to swallow their prey up as well. The prominent tusk is being used to push and stun small prey, making capturing easier.