Scientists once filed rabbits with the rodents. A paleontologist named Gidley proposed in 1912 that they get their own order, Lagomorpha, partly because of the second small peg teeth behind their upper front teeth. A rabbit has two pairs of upper front teeth, a big pair with a small peg tooth behind each, while a rodent has only one pair. Rabbits, hares and pikas used to be classed as a family inside the rodent order, under the name Duplicendentata; differences in their teeth led to a separate order, Lagomorpha. Many studies place lagomorphs and rodents together in a group called Glires, which suggests a shared ancestor, but some molecular studies disagree. In 1996, protein sequencing of rabbits, primates and rodents suggested that lagomorphs are more closely related to primates than to rodents, and this is one example of how unsettled the rabbit family tree is. Exactly where rabbits belong in the mammal family tree is still debated.
Most rabbits and hares seem to have arisen in one rapid burst of new species during the mid- to late Miocene, between 12 and 16 million years ago, in central Asia, according to molecular evidence. Every domestic rabbit, in about 80 varieties, descends from the European rabbit, Oryctolagus cuniculus. Because of people, European rabbits now live in the wild on every continent except Asia and Antarctica, although the last Ice Age had left them only in Iberia and nearby areas. Settlers brought the eastern cottontail to New England before 1900, and it now competes with the native New England cottontail for the same places to live. A 2014 study in the journal Science compared the genomes of wild and domestic rabbits, and genes affecting brain and neuronal development were often targeted during domestication. The same study proposed that tame behavior in rabbits and other domestic animals evolved through small shifts at many genes, not through critical changes at only a few. As of November 2026, the native New England cottontail's numbers have been steadily declining because it competes with the eastern cottontail, which uses many of the same resources and habitats.
A rabbit's eyes sit high on the sides of its head, so it can spot danger from almost any direction, and it can see almost all the way around its head. Rabbits are one of the few mammals whose vision is not solely binocular, because their eyes sit on the sides of the head, which gives them a broad field of view: front, rear, upward and downward. A rabbit has a blind spot under its chin and in front of its nose, and its retina has a much higher ratio of rods to cones than a human retina; it sees better than a person in dim light, but the dim-light picture is grainy. Rabbits have limited color vision: they can tell green from blue, probably with two kinds of cone cells, but they do not see color as people do.
The ears do several jobs at once. The big ears of a rabbit are also a cooling system; its ears are highly vascular and make up about 12 percent of its body surface, and a counter-current heat exchange system helps them regulate body temperature. A rabbit can move each of its big ears on its own to find where a sound is coming from, and its ears show how it feels: ears close together, upright and pointing outward mean a relaxed rabbit, but ears flat against the back mean a worried one. Many rabbits and hares have white fur under the tail, which they silently flash to warn others that a predator is near. A rabbit may thump its back feet on the ground to warn of danger, and a cottontail that senses danger may freeze in place or dash away.
Plants are full of cellulose and lignin, which mammals cannot digest on their own. A rabbit relies on a cecum up to ten times longer than its stomach, full of microbes that break these fibers down; a rabbit has a very large cecum, a pouch in its gut where plant food ferments. Rabbits make soft cecotrophs mostly in the morning and evening, about four hours after feeding, and they eat them to get extra nutrients. Rabbits also eat some of their own soft droppings to get more food value from plants, and scientists have suggested that rabbits and hares began re-eating soft droppings partly so they could stay safe inside burrows while still getting enough nutrients. A rabbit's front teeth grow about 2 to 3 millimeters every week, which is why a pet rabbit needs hay: chewing it grinds the teeth down side to side.
A jackrabbit is not a rabbit but a hare, and hares live mostly in open country, while rabbits stay close to thick cover. Hares and rabbits have hind legs much longer than their forelegs, which lets them run in a zigzag that makes it harder for a chaser to follow; hares tend to outrun trouble, and rabbits tend to dash for cover or a burrow. A black-tailed jackrabbit can spring 20 feet in one bound and reach 30 to 35 miles per hour on a zigzag course, which is much faster than a cottontail. Black-tailed jackrabbits live in dry places and get nearly all the water they need from the plants they eat. The snowshoe hare, a close relative of rabbits, changes color with the seasons: its summer coat is rusty or grayish brown, and in winter its fur turns almost entirely white. Its numbers swing wildly, as their density can go from 1 to 10,000 hares per square mile.
Life underground is organized by rank. Some wild rabbits live in underground homes called warrens. Rabbits in a warren live in groups; a typical group has six to ten adults, and a big warren can hold up to 30 rabbits and spread across two acres or more. European rabbit colonies have dominance hierarchies, which matter most for males, because a male's rank decides which male gets first access to mates, so costly fights over females are rare. In large warrens, the most dominant does get the best nest sites. Low-ranking European rabbits may be pushed into breeding in single-entrance burrows called stops, away from the main warren. Rank shapes who mates first, who nests in the best places, and who is pushed away from the main warren. The pygmy rabbit is the smallest rabbit in North America, and it digs its own burrow; a pregnant pygmy rabbit digs a secret, shallow nursery burrow, and after nursing, she fills the entrance with loose soil to hide it.
Rabbit society leaves marks that scientists can read. In a free-living population of wild European rabbits, stable breeding groups became genetically distinct units with little gene flow between them, because the social behavior of the rabbits shaped their genetic structure. In that study, females tended to stay in their home group while males tended to move away, so females in a group were more closely related to each other than males were. Two lines of evidence show how far these effects reach, and the same animals that live together underground also change the land above them. European rabbits are also ecosystem engineers: grazing, pawscraping and burrowing create a mosaic of vegetation that can benefit grassland, heath and dune habitats, and mosses, lichens and other species. Rabbit warrens also shelter other species, including small mammals, invertebrates, and even reptiles and amphibians, which supports wider biodiversity. As of November 2026, in Washington State's Columbia Basin, the remaining pygmy rabbit population is endangered. Its shrub-steppe home has been broken up, and wildfires have increased.
A baby rabbit is called a kit, and baby cottontails are born with no fur and cannot see; they open their eyes when they are about a week old. A cottontail mother scrapes a shallow dip in the ground for her nest instead of digging a burrow, and she lines her nest with grass and her own fur. A mother rabbit stays away from her nest most of the day and visits only briefly to feed her babies, and young cottontails leave the nest when they are two to three weeks old, and they are on their own when they are about a month old. An eastern cottontail mother usually has two to four litters a year, and she can have another litter soon after she has had one. Most wild eastern cottontails live only two or three years.
A young wild cottontail about the size of a softball, with its eyes open and its ears held upright, can take care of itself and should be left alone. A hutch alone is not enough for a pet rabbit. It needs room to move, play, exercise and hide: at least 3 by 2 by 1 meters, about 10 by 6.5 by 3 feet. Pet rabbits eat mostly hay and should eat only a few pellets; they need other rabbits for company, and two pet rabbits should meet slowly, on neutral ground. They also need toys they can chew and dig in, and a rabbit loose in a room must be kept safe from chewing electrical cords; a rabbit has a fragile backbone, so it must be held gently and kept from struggling, and it should never be picked up by its ears. A pet rabbit can live for 8 to 12 years and needs a lot of time and care.
Words to know
- Lagomorpha: rabbit order
- cecum: gut pouch
- hierarchies: rank orders
- binocular: two-eyed overlapping view
- domestication: taming over generations
