Common Rodents

• Norway Rat

  Also referred to as the common rat, sewer rat, brown rat and water rat.

  The Norway rat is the larger of the two pest rats and has a thickset body, blunt snout, small close—set ears and a tail shorter than its body length. It normally lives 9—18 months and may have 5—6 litters per year (each With 8—10 young). The young achieve sexual maturity at 3—4 months. Clearly, its reproductive potential is very high.

  The Norway rat is very widespread and is possibly the most economically detrimental pest rodent in Australia. It infests warehouses, factories, flour mills, poultry farms, garbage dumps, shops, supermarkets, domestic premises, grain storage facilities, sewers, and many other locations that ofler shelter and food. Outside buildings, these rats mostly live in burrows, which tunnel into stream banks, under buildings, under rubbish heaps and so on. Burrows commonly have ‘bolt holes’ hidden under debris or grass to facilitate fast emergency exits. They may enter buildings just for food, reside in buildings during the colder winter months, or live in buildings all year round. Nests in buildings are mostly located in wall voids, roof voids and other parts of the construction that offer a secretive, undisturbed area for shelter and access to food and water.

• Roof Rat

  Also referred to as the black rat and ship rat.

  The roof rat is the smaller of the pest rats and is of slighter build. It has a more pointed snout, large prominent ears and a tail longer than its body length. It normally lives 9—18 months and may have 4—5 litters per year (each With 6—8 young). The young achieve sexual maturity at 3—4 months. The roof rat activity is mostly restricted to the indoors of premises and to structures.

• House Mouse

  Also referred to, euphemistically, as the field mouse by people who don’t want to admit they have the pest mouse.

  The house mouse is small and has rather large ears, a pointed snout and a tail at least as long as its body length. House mice living indoors are usually a darkish grey colour, With lighter grey on the belly, While those living mainly outdoors tend to a more sandy or yellow—brown colouring — hence the references to ‘field mice’. They tend to live for about one year and may have 6—10 litters per year (each With 5—6 young). The young achieve sexual maturity at about six weeks.

  The house mouse may live indoors or out of doors, sometimes entering buildings only when climatic conditions are adverse. Being such small animals, their access into buildings is probably easier than for rats, and a greater range of nesting sites is available to them. Typically, within buildings they may nest in wall voids, cupboards, roof voids, stored foods, furniture and many other locations. Out of doors, they live in burrows.