Occasionally, the burrow of some other animal, such as the badger, is taken over and remodeled to suit the new occupants. Red foxes are opportunistic feeders and will take any acceptable food in proportion to its availability. The major food items are small rodents, rabbits, wild fruits and berries, and insects. Small mammals evidently constitute staple foods during the greater part of the year. Other kinds of prey fluctuate according to season, weather conditions, abundance, and vulnerability of prey populations, and with the experience of the fox.
Young animals learning to hunt have to take what they can get.
Female red foxes have a single estrous each year and reputedly remain mated for life. Males and females pair off and mate from late December to January or February. Females have a very short period of heat that lasts only 2-4 days. The female establishes the den site for the young in late winter, but both parents live together while raising the young. Foxes either dig their own dens or utilize those of other burrowing animals.