Their whole body organization and manner of living are adapted for predation. The diet may vary by season and locality. Some species regularly eat carrion. Arctictis is largely frugivorous, and the diet of certain other viverrids consists partly of fruit. The Procyonidae and Ursidae, except for the carnivorous polar bear, are omnivorous, eating a wide variety of plant and animal life.
Carnivores are solitary or associate in pairs or small groups.
Females commonly produce a single litter each year, but those of a few species may give birth two or three times annually, and those of some large species usually mate at intervals of several years. Most species have gestation periods of about 49-113 days. Delayed implantation of the fertilized egg occurs in ursids and some mustelids, so the period from mating to birth is considerably longer than average. Litter size commonly ranges from 1 to 13. The offspring usually are born blind and helpless, but with a covering of hair.