The Rodents that are of great concern in the urban area, not just in Australia, but in many countries, are the Norway rat, Roof rat and the House Mouse.
Eating & contamination of stored foods.

Rats and mice are responsible for enormous losses of food in store, either by directly eating the foods or by rendering them inedible through contamination. As the rodents move in and around stored foods they contaminate the food with droppings .

Gnawing: physical damage.

Typically, they may damage doors, skirting's and other parts of buildings, upholstery, books, food containers or packaging, and parts of equipment or machinery. The gnawing of wires and cables has caused the breakdown of telephone systems and short-circuiting, which may result in equipment breakdown or, at worst, very costly fires. Fire damage has also resulted from the gnawing of matches collected in the nest.

Disease Transmission.

Among the many diseases transmitted to humans by rodents,the most insidious and widespread problem involves the distribution of food - poisoning organisms (eg Salmonella bacteria).