Red foxes are opportunist feeders and eat insects, earthworms, fruit, berries, wild birds, small mammals and scraps left by humans. They are primarily active at dusk and night. They are solitary, but they will very occasionally group together in a pack. Foxes forage alone in different parts of their territory, which may extend from 25 to 5,000 acres, depending on the habitat. Faeces and urine mark territories.