Although they are shy creatures, in urban areas you are never more than 12 feet from a rat (Usually Rattus norvegicus). Being very caring of their young, the growing rat population is an ever increasing hazard. They spread many diseases including the water-borne and potentially fatal leptospirosis. They also cause considerable structural and product damage and must be dealt with using the most efficient control programme.

House mice (Mus musculus) continually urinate leaving a trail over areas, sometimes coming into contact with food. Many outbreaks of severe food poisoning (Salmonella contamination) have been caused in this way. Like rats they are also responsible for leptospirosis but, unlike them, they are social in their behaviour, very inquisitive about things in their environment, and readily explore anything new.