Both species of Rat found in Great Britain the Common, Brown or Norway rat (Rattus norvegicus) and the Black Rat (Rattus Rattus) and the house mouse (Mus domesticus) are collectively known as Commensal Rodents. Commensal is derived from Latin: com meaning together and “Mensa” meaning table. Put simply they share our table, or more importantly food.

Rodents can and do inhabit any area close to an available food source, although they will tend to make their nests in dark spaces where they feel safe

Commensal Rodents can may give birth every 24 -28 days and this can give rise to a rapidly increasing population; although this population will be held in check by the amount of resources (food) available to the population it can lead to a staggering growth in the population in a comparatively short time-scale.

Wild rodents, including rats, can carry many different zoonotic pathogens, such as Leptospira, Toxoplasma gondii, and Campylobacter. The Black Death is traditionally believed to have been caused by the micro-organism Yersinia pestis, carried by the tropical rat flea (Xenopsylla cheopis) which preyed on black rats living in European cities during the epidemic outbreaks of the Middle Ages; these rats were used as transport hosts. Other zoonotic diseases linked to pest rodents include classical swine fever and foot-and-mouth disease.