An invasive species: that's what cats are now termed by biologists around the world. Yet they are the most popular house pet on the planet. How one animal can be both is a distinct tribute to the adaptability of the cat.

Domestic cats (also known as housecats) are felines, part of the felids category of animals. This subcategory includes many small and medium-sized cats and even some larger ones (cheetahs are notably part of this category, as well as jaguarundi and mountain lions). Archaelogically, the earliest records of the feline that have been unearthed to date are those of felis attica in western Eurasia during the late Miocene geological period, roughly 23 million to 5 million years before the present time (scientifically described as 23.03 to 5.33 Ma.

For nearly 10,000 years, the domestic cat has been part of our lives, both because of its utility as an eliminator of all sorts of vermin and because of its companionship. Archaelogists in 2007 found a grave in Cyprus where a kitten was buried with its owner; the grave dates from approximately 9,000 years ago.

Today, feral cats threaten all sort of small native species around the world, which led to the biological classification of invasive species for the cat. Simultaneously, there hundreds of millions of cats beloved as housepets worldwide with new breeds being created all the time. There are currently 40 breeds recognized for championship status by the Cat Fanciers Association; the International Progressive Cat Association recognizes 73.