Dramatic color variations may occur in individual reds, although these are rare and show up more often in the species' northern range, especially in Canada. Foxes are swift runners and can swim if they have to. Both reds and grays are mainly nocturnal. This means they will eat whatever is most easily obtained. Foods include mice, rats, rabbits, woodchucks, opossums, porcupines, domestic cats, chickens, insects, squirrels, game birds, songbirds, bird eggs, fruits and grasses.
Foxes are also scavengers, feeding on road-killed animals and winter kills.
Diets of both reds and grays are essentially the same, but different food preferences, behavior patterns and preferred habitat often result in different types and amounts of food eaten. Both species cache uneaten food by burying it in loose earth. In late winter, foxes can be heard barking at night, making their presence known to members of the opposite sex. Breeding usually takes place in February. Litters range from 4-10 young, with six the average.