European rabbit in the context of Warren (burrow)

An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. Since the 20th century, invasive species have become serious economic, social, and environmental threats worldwide.

Invasion of long-established ecosystems by organisms is a natural phenomenon, but human-facilitated introductions have greatly increased the rate, scale, and geographic range of invasion. For millennia, humans have served as both accidental and deliberate dispersal agents, beginning with their earliest migrations, accelerating in the Age of Discovery, and accelerating again with the spread of international trade. Notable invasive plant species include the kudzu vine, giant hogweed (Heracleum mantegazzianum), Japanese knotweed (Reynoutria japonica), and yellow starthistle (Centaurea solstitialis). Notable invasive animals include European rabbits (Oryctolagus cuniculus), domestic cats (Felis catus), and carp (family Cyprinidae).

Rabbits or bunnies 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.

European rabbits (Oryctolagus cuniculus) were first introduced to Australia in the 18th century with the First Fleet, and later became widespread, because of Thomas Austin. Such wild rabbit populations are a serious mammalian pest and invasive species in Australia causing millions of dollars' worth of damage to crops. Their spread may have been enhanced through the emergence of strong crossbreeds.

Various methods in the 20th century have been attempted to control the Australian rabbit population. Conventional methods include shooting rabbits and destroying their warrens, but these had only limited success. From 1901 to 1907, a rabbit-proof fence was built in Western Australia in an unsuccessful attempt to contain the rabbits. The myxoma virus, which causes myxomatosis, was introduced into the rabbit population in the 1950s and had the effect of severely reducing the rabbit population. However, the survivors have since adapted and partially recovered their previous numbers. Domesticated rabbits are banned as pets in the state of Queensland.

The domestic rabbit (Oryctolagus cuniculus domesticus) is the domesticated form of the European rabbit. There are hundreds of rabbit breeds originating from all over the world. Rabbits were first domesticated and used for food and fur by the Romans. Rabbits may be housed inside, but the idea of the domestic rabbit as a house companion, a so-called house rabbit (similar to a house cat), was only strongly promoted starting with publications in the 1980s. Rabbits can be trained to use a litter box and taught to come when called, but require exercise and can damage a house or injure themselves if it has not been suitably prepared, based on their innate need to chew. Accidental interactions between pet rabbits and wild rabbits, while seemingly harmless, are strongly discouraged due to the species' different temperaments as well as wild rabbits potentially carrying diseases.

Unwanted pet rabbits sometimes end up in animal shelters, especially after the Easter season. In 2017, they were the United States' third most abandoned pet. Some of them go on to be adopted and become family pets in various forms. Because their wild counterparts have become invasive in Australia, pet rabbits are banned in the state of Queensland. Domestic rabbits — bred for generations under human supervision to be docile — lack survival instincts, and perish in the wild if they are abandoned or escape from captivity.

An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. Since the 20th century, invasive species have become serious economic, social, and environmental threats worldwide.

Invasion of long-established ecosystems by organisms is a natural phenomenon, but human-facilitated introductions have greatly increased the rate, scale, and geographic range of invasion. For millennia, humans have served as both accidental and deliberate dispersal agents, beginning with their earliest migrations, accelerating in the Age of Discovery, and accelerating again with the spread of international trade. Notable plant species that are invasive in North America include the kudzu vine (Pueraria), giant hogweed (Heracleum mantegazzianum), Japanese knotweed (Reynoutria japonica), and yellow starthistle (Centaurea solstitialis). Notable animal species that are invasive in North America include European rabbits (Oryctolagus cuniculus), domestic cats (Felis catus), and carp (family Cyprinidae).