A red fox hunts by moving back and forth over an area, finding food by scent and sound. The red fox is mainly a hunter at dusk and at night, and it must rely mainly on hearing to find food. It can hear low sounds very well, including rodents digging underground, and it can hear small animals it cannot see, such as a mouse under snow or hidden in leaves. A fox that is hunting a mouse can stand still and listen for it. It creeps close, the way a cat does, and then pounces: a fox that has found a mouse launches itself into the air at a 45-degree angle and lands on it, pinning it to the ground. Researchers in the Czech Republic observed 84 wild red foxes jump at small prey and recorded 592 jumps.

Red foxes are omnivores, which means they eat both plants and animals, and a red fox eats approximately half a kilogram to one kilogram of food each day. They eat rodents and rabbits, and they also eat fruit. Voles are a favorite food of red foxes; where meadow voles are common, they can make up as much as 50 percent of a red fox's diet. Red foxes help to control the numbers of rodents and rabbits. A red fox can store extra food by hiding it, in a den or buried in the ground, and it may partly bury extra food, cover it with soil, grass, leaves or snow, and mark it with urine.

A red fox den is a hole in the earth 15 to 20 feet long, usually on the side of a knoll, and red foxes often use an old woodchuck burrow as a den instead of digging their own. A red fox litter averages approximately five kits. A newborn red fox weighs approximately 96 g (3.4 oz) and is covered with fine gray fur, and red fox kits open their eyes 9 to 14 days after birth. Newborn kits stay at the den for the first month, and at 10 weeks old they may travel short distances from it without a parent. Red fox kits are weaned when they are 8 to 10 weeks old; in New Jersey, parental care continues until the young foxes reach adult size at 6 to 7 months of age.

Red foxes mark their home ranges with scent, and a red fox usually stays in the same home range for life. A red fox range is held by one adult male and one or two adult females with their young. How big a home range is depends on its habitat and on how much food is there. In Connecticut, the normal home range for a red fox is approximately 2 to 4 square miles, and in New Jersey and other temperate places, red foxes typically range over 2 to 8 square miles. Red foxes can disperse, or move away to a new area, as far as almost 400 km, or as near as 10 km. A red fox with kits usually stays within a mile of its den while the kits are growing up.

Words to know

• prey: hunted animals
• disperse: move away
• temperate: mild weather
• knoll: a small hill