For the first several weeks, kittens cannot urinate or defecate without being stimulated by their mother.[6] They also cannot regulate their body temperature for the first three weeks, so kittens born in temperatures less than 27 °C (81 °F) can die from hypothermia if their mother does not keep them warm.[7] The mother's milk is very important for the kittens' nutrition and proper growth. This milk transfers antibodies to the kittens, which helps protect them against infectious disease.[8] Newborn kittens are unable to produce concentrated urine, and so have a very high requirement for fluids.[9] Kittens open their eyes about seven to ten days after birth. At first, the retina is poorly developed and vision is poor. Kittens cannot see as well as adult cats until about ten weeks after birth.[10]
^ Jump up to: a b Ottoni, C.; Van Neer, W.; De Cupere, B.; Daligault, J.; Guimaraes, S.; Peters, J.; Spassov, N.; Prendergast, M. E.; Boivin, N.; Morales-Muñiz, A.; Bălăşescu, A.; Becker, C.; Benecke, N.; Boroneant, A.; Buitenhuis, H.; Chahoud, J.; Crowther, A.; Llorente, L.; Manaseryan, N.; Monchot, H.; Onar, V.; Osypińska, M.; Putelat, O.; Quintana Morales, E. M.; Studer, J.; Wierer, U.; Decorte, R.; Grange, T.; Geigl, E. (2017). "The palaeogenetics of cat dispersal in the ancient world". Nature Ecology & Evolution. 1 (7): 0139. doi:10.1038/s41559-017-0139. ISSN 2397-334X.

Cats hunt small prey, primarily birds and rodents,[155] and are often used as a form of pest control.[156][157] Domestic cats are a major predator of wildlife in the United States, killing an estimated 1.4 to 3.7 billion birds and 6.9 to 20.7 billion mammals annually.[158][159] The bulk of predation in the United States is done by 80 million feral and stray cats. Effective measures to reduce this population are elusive, meeting opposition from cat enthusiasts.[158][159] In the case of free-ranging pets, equipping cats with bells and not letting them out at night will reduce wildlife predation.[155]
In 2003, the International Commission on Zoological Nomenclature (ICZN) fixed the scientific name for the wildcat as F. silvestris. The same commission ruled that the domestic cat is a distinct taxon Felis catus.[40][41] Following results of phylogenetic research, the domestic cat was considered a wildcat subspecies F. silvestris catus in 2007.[42][43]
Cats is completely told through music with no dialogue in between the songs,[74] although there are occasions when the music accompanies spoken verse. Lloyd Webber's compositions employ an eclectic range of musical styles so as to magnify the characters' contrasting personalities.[4] For example, the rebellious Rum Tum Tugger is introduced with a rock song ("The Rum Tum Tugger"); the fallen Grizabella is accompanied by a dramatic operatic aria ("Grizabella: The Glamour Cat"); Old Deuteronomy makes his grand entrance to a lullaby-turned-anthem ("Old Deuteronomy"); and Gus' nostalgia for the past is reflected through an old-fashioned music hall number ("Gus: The Theatre Cat").[16] Many of the songs are pastiches of their respective genres, which Snelson attributes to the show's origins as a song cycle:
Female cats are seasonally polyestrous, which means they may have many periods of heat over the course of a year, the season beginning in spring and ending in late autumn. Heat periods occur about every two weeks and last about 4 to 7 days.[178] Multiple males will be attracted to a female in heat. The males will fight over her, and the victor wins the right to mate. At first, the female rejects the male, but eventually the female allows the male to mate. The female utters a loud yowl as the male pulls out of her because a male cat's penis has a band of about 120–150 backwards-pointing penile spines, which are about 1 mm long; upon withdrawal of the penis, the spines rake the walls of the female's vagina, which acts to induce ovulation. This act also occurs to clear the vagina of other sperm in the context of a second (or more) mating, thus giving the later males a larger chance of conception.[179]

Dance plays a major role in Cats as the creative team had specifically set out to create "England's first dance musical".[81] Before Cats, the industry-wide belief was that British dancers were inferior to their Broadway counterparts. The risky hiring of a British choreographer, Lynne, for a British dance musical was described by one historian as "a vivid and marvellous gesture of transatlantic defiance".[82] Making Lynne's job more challenging was the fact that the music in Cats is unceasing and the majority of the cast remains onstage throughout nearly the entire show.[82]
The original Viennese cast included Ute Lemper who played Bombalurina, Steve Barton who played Munkustrap, and Robert Montano who played Pouncival.[112] Pia Douwes was also a member of the cast from 1987 to 1989, covering several different characters including Grizabella.[175] The Vienna production also performed limited runs at the Komische Oper Berlin in East Germany in 1987,[176] and at the Moscow Operetta Theatre in the Soviet Union in 1988.[177]

The origin of the English word cat (Old English catt) and its counterparts in other Germanic languages (such as German Katze), descended from Proto-Germanic *kattōn-, is controversial. It was thought traditionally to be a borrowing from Late Latin cattus, 'domestic cat', from catta (used around 75 AD by Martial),[22][23] compare also Byzantine Greek κάττα, Portuguese and Spanish gato, French chat, Maltese qattus, Lithuanian katė, and Old Church Slavonic kotъ (kot'), among others.[24]