DuMOR Classic Diet Corn-Free Pet Rabbit Food, 20 lb.

Twenty or 20 may refer to:

• 20 (number), the natural number following 19 and preceding 21
• one of the years 20 BC, AD 20, 1920, 2020

A classic is an outstanding example of a particular style; something of lasting worth or with a timeless quality; of the first or highest quality, class, or rank – something that exemplifies its class. The word can be an adjective (a classic car) or a noun (a classic of English literature). It denotes a particular quality in art, architecture, literature, design, technology, or other cultural artifacts. In commerce, products are named 'classic' to denote a long-standing popular version or model, to distinguish it from a newer variety. Classic is used to describe many major, long-standing sporting events. Colloquially, an everyday occurrence (e.g. a joke or mishap) may be described in some dialects of English as 'an absolute classic'.

"Classic" should not be confused with classical, which refers specifically to certain cultural styles, especially in music and architecture: styles generally taking inspiration from the Classical tradition, hence classicism.

Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin and contains essential nutrients such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism and assimilated by the organism's cells to provide energy, maintain life, or stimulate growth. Different species of animals have different feeding behaviours that satisfy the needs of their metabolisms and have evolved to fill a specific ecological niche within specific geographical contexts.

Omnivorous humans are highly adaptable and have adapted to obtain food in many different ecosystems. Humans generally use cooking to prepare food for consumption. The majority of the food energy required is supplied by the industrial food industry, which produces food through intensive agriculture and distributes it through complex food processing and food distribution systems. This system of conventional agriculture relies heavily on fossil fuels, which means that the food and agricultural systems are one of the major contributors to climate change, accounting for as much as 37% of total greenhouse gas emissions.

The food system has significant impacts on a wide range of other social and political issues, including sustainability, biological diversity, economics, population growth, water supply, and food security. Food safety and security are monitored by international agencies like the International Association for Food Protection, the World Resources Institute, the World Food Programme, the Food and Agriculture Organization, and the International Food Information Council.

A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive/cute appearances, intelligence, and relatable personalities, but some pets may be taken in on an altruistic basis (such as a stray animal) and accepted by the owner regardless of these characteristics.

Two of the most popular pets are dogs and cats. Other animals commonly kept include rabbits; ferrets; pigs; rodents such as gerbils, hamsters, chinchillas, rats, mice, and guinea pigs; birds such as parrots, passerines, and fowls; reptiles such as turtles, lizards, snakes, and iguanas; aquatic pets such as fish, freshwater snails, and saltwater snails; amphibians such as frogs and salamanders; and arthropod pets such as tarantulas and hermit crabs. Smaller pets include rodents, while the equine and bovine group include the largest companion animals.

Pets provide their owners, or guardians, both physical and emotional benefits. Walking a dog can provide both the human and the dog with exercise, fresh air, and social interaction. Pets can give companionship to people who are living alone or elderly adults who do not have adequate social interaction with other people. There is a medically approved class of therapy animals that are brought to visit confined humans, such as children in hospitals or elders in nursing homes. Pet therapy utilizes trained animals and handlers to achieve specific physical, social, cognitive, or emotional goals with patients.

People most commonly get pets for companionship, to protect a home or property, or because of the perceived beauty or attractiveness of the animals. A 1994 Canadian study found that the most common reasons for not owning a pet were lack of ability to care for the pet when traveling (34.6%), lack of time (28.6%), and lack of suitable housing (28.3%), with dislike of pets being less common (19.6%). Some scholars, ethicists, and animal rights organizations have raised concerns over keeping pets because of the lack of autonomy and the objectification of non-human animals.

Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated form of livestock, and a pet, having a widespread effect on ecologies and cultures. The most widespread rabbit genera are Oryctolagus and Sylvilagus. The former, Oryctolagus, includes the European rabbit, Oryctolagus cuniculus, which is the ancestor of the hundreds of breeds of domestic rabbit and has been introduced on every continent except Antarctica. The latter, Sylvilagus, includes over 13 wild rabbit species, among them the cottontails and tapetis. Wild rabbits not included in Oryctolagus and Sylvilagus include several species of limited distribution, including the pygmy rabbit, volcano rabbit, and Sumatran striped rabbit.

Rabbits are a paraphyletic grouping, and do not constitute a clade, as hares (belonging to the genus Lepus) are nested within the Leporidae clade and are not described as rabbits. Although once considered rodents, lagomorphs diverged earlier and have a number of traits rodents lack, including two extra incisors. Similarities between rabbits and rodents were once attributed to convergent evolution, but studies in molecular biology have found a common ancestor between lagomorphs and rodents and place them in the clade Glires.

Rabbit physiology is suited to escaping predators and surviving in various habitats, living either alone or in groups in nests or burrows. As prey animals, rabbits are constantly aware of their surroundings, having a wide field of vision and ears with high surface area to detect potential predators. The ears of a rabbit are essential for thermoregulation and contain a high density of blood vessels. The bone structure of a rabbit's hind legs, which is longer than that of the fore legs, allows for quick hopping, which is beneficial for escaping predators and can provide powerful kicks if captured. Rabbits are typically nocturnal and often sleep with their eyes open. They reproduce quickly, having short pregnancies, large litters of four to twelve kits, and no particular mating season; however, the mortality rate of rabbit embryos is high, and there exist several widespread diseases that affect rabbits, such as rabbit hemorrhagic disease and myxomatosis. In some regions, especially Australia, rabbits have caused ecological problems and are regarded as a pest.

Humans have used rabbits as livestock since at least the first century BC in ancient Rome, raising them for their meat, fur and wool. The various breeds of the European rabbit have been developed to suit each of these products; the practice of raising and breeding rabbits as livestock is known as cuniculture. Rabbits are seen in human culture globally, appearing as a symbol of fertility, cunning, and innocence in major religions, historical and contemporary art.