Rodents contaminate more food than they eat and in so doing, they transmit many diseases. In conjunction with the flea, rats were responsible for the deaths of 200 million Europeans from bubonic plague.
The three major pest species are the Norway Rat, the Roof Rat and the House Mouse. They are common in the major population centres of Australia and most countries of the world. As climatic conditions become less favourable during the onset of winter, rodents move indoors for both shelter and food. In commercial premises, rodents can be a year-round problem and mice can attain plague proportions especially in rural areas.
Rodents make their nests of soft materials such as shredded paper or fabrics, close to areas where they scavenge for food and water. Females are capable of giving birth to 4-6 litters a year, each litter containing 5-10 young, which are themselves capable of reproduction three months after birth. Within a year, the progeny of a single pair of rodents can number 400-700.
Rodents actively forage for food at night using the same route to and from the food source. Their diet includes food material of both plant and animal origin and water is a necessity especially for rats. Mice can obtain enough water from food provided it’s moist.
Although the vision of rodents is poor, their senses of smell and taste are so highly developed they can detect minute quantities of chemicals in foodstuffs which can lead to ‘bait shyness’. Their whiskers and guard hairs enable them to feel their way in their preferred darkness with little difficulty.