Rattus Maximus Traditional Geocache

The Black Rat (Rattus rattus) also known as the Ship Rat, Roof Rat or House Rat is a common long-tailed rodent of the genus Rattus. The species originated in tropical Asia and spread through the Near East in Roman times before reaching Europe in the 8th Century and spreading with Europeans across the world.

It is largely confined to warmer areas, having been supplanted by the Brown rat (Rattus norvegicus) in cooler regions. Despite its name it comes in several colour forms and is a poor swimmer. It is usually black to light brown in colour with a lighter underside. A typical rat will be 20 cm long with a further 20 cm of tail.

It is agile and climbs well, tending even to flee upwards. It is nocturnal and omnivorous, with a preference for grains although it spoils more than it consumes. In a suitable environment it will breed throughout the year, with a female producing three to six litters a year of up to twenty young. A rat can live for up to four years. Social groups of up to sixty can be formed.

Black rats are able to carry a number of pathogens, of which bubonic plague (via the rat flea), typhus, Weil's disease, toxoplasmosis and trichinosis are the best known. It has been hypothesised that the displacement of black rats by brown rats led to the decline of the Black Death. This theory has, however, been deprecated.