types of animal, notably monkeys, have never been domesticated but are still sold and kept as pets. There are also inanimate objects that have been kept as "pets", either as a form of a game or humorously (e.g. the Pet Rock or Chia Pet). Some wild animals are kept as pets, such as tigers, even though this is illegal. There is a market for illegal pets. Domesticated Domesticated pets are most common. A domesticated animal is a species that has been made fit for a human environment by being consistently kept in captivity and selectively bred over a long enough period of time that it exhibits marked differences in behavior and appearance from its wild relatives. Domestication contrasts with taming, which is simply when an un-domesticated, wild animal has become tolerant of human presence, and perhaps even enjoys it. Large mammals that might be kept as pets include: alpaca, camel, cattle, donkey, goat, horse, llama, pig, and sheep. Small mammals that might be kept as pets include: ferret, hedgehog, rabbit, sugar glider, and rodents, including rat, mouse, hamster, guinea pig, gerbil, and chinchilla. Other mammals include cat, dog, monkey, and domesticated silver fox. Birds kept as pets include companion parrots like the budgie and cockatiel, fowl such as chickens, turkeys, ducks, geese, and quail, columbines, and passerines, namely finches and canaries. Fish kept as pets include: goldfish, koi, Siamese fighting fish (Betta), barb, guppy, molly, Japanese rice fish (Medaka), and oscar. Arthropods kept as pets include bees, such as honey bees and stingless bees, Silk moth, and ant farms. Reptiles and amphibians kept as pets include snakes, turtles, axolotl, frogs and salamanders. Wild animals Wild animals are kept as pets. The term “wild” in this context specifically applies to any species of animal which has not undergone a fundamental change in behavior to facilitate a close co-existence with humans. Some species may have been bred in captivity for a considerable length of time, but are still not recognized as domesticated. Generally, wild animals are recognized as not suitable to keep as pets, and this practice is completely banned in many places. In other areas, certain species are allowed to be kept, and it is usually required for the owner to obtain a permit. It is considered animal cruelty by some, as most often, wild animals require precise and constant care that is very difficult to meet in captive conditions. Many