Members stay with the pod long-term, some recorded as 15 years, and, indicated by mass strandings, share strong bonds with other members. It is thought it has a matrifocal family structure, with the mothers heading the pod instead of the father, like in sperm whales and pilot whales. Different populations around the world have different vocalizations, similar to other dolphins. The false killer whale is probably polygynous, with males mating with multiple females. Generally, the false killer whale targets a wide array of squid and fish of various sizes during daylight hours. They typically target large species of fish, such as mahi-mahi and tuna. In captivity, it eats 3.4 to 4.3% of its body weight per day. A video taken in 2016 near Sydney shows a group hunting a juvenile shark. It sometimes discards the tail, gills, and stomach of captured fish, and pod members have been known to share food. In the Eastern Pacific, the false killer whale has been known to target smaller dolphins during tuna purse-seine fishing operations; there are cases of attacks on sperm whales ("Physeter macrocephalus"), and one instance against a calf of a humpback whale ("Megaptera novaeangliae"). Killer whales are known to prey on the false killer whale, and it also possibly faces a threat from large sharks, though there are no documented instances. The false killer whale is a known host of several parasites: trematode "Nasitrema" in the sinuses, nematode "Stenurus" in the sinuses and lungs, an unidentified crassicaudine nematode in the sinuses, stomach nematodes "Anisakis simplex" and "Anisakis typica", acanthocephalan worm "Bolbosoma capitatum" in the intestines, whale lice "Syncyamus pseudorcae" and "Isocyamus delphinii", and the whale barnacle "Xenobalanus globicipitus". Some strandings had whales with large "Bolbosoma" infestations, such as the 1976 and 1986 strandings in Florida. The false killer whale appears to have a widespread presence in tropical and semitropical oceanic waters. The species has been found in temperate waters, but these occurrences were possibly stray individuals, or associated with warm water events. It generally does not go beyond 50°N and below 50°S. It usually inhabits open oceans and deep-water areas, though it may frequent coastal areas near oceanic islands.