Main Rodent Species
I. Norway Rat
Scientific Name: Rattus norvegicus (Berkenhout)
Order/Family: Rodentia/Muridae
Biology: The female Norway rat produces up to 48 young during her life.
II. Black Rat (Roof Rat)
Scientific Name: Rattus rattus (Linnaeus)
Order/Family: Rodentia/Muridae
Biology: The female Roof rat produces up to 48 young during her life.
III. House Mouse
Scientific Name: Mus musculus (Linnaeus)
Order/Family: Rodentia/Muridae
Biology: The female House mouse produces up to 48 young during her life.
Rodent health significance: Rodent associated with pathogens causing various diseases such as; Plague, Murine typhus, Rickettsial pox, Salmonellosis, Rat-bite fever, Leptospirosis (weils disease), Lymphocytic choriomeningitis, Trichinosis, Typhoid, Dysentery and several other diseases.
The economic implications of rodents:
- The FAO of the United Nations reported in 1982 that rats destroyed more than 42 million tons of food worth $30 billion.
- Between one-fifth to one third of world's food supply never reaches the table due to losses from rodents.
- Rat can consume up to 28 gram of food each evening, considering a realistic population of 50 rats living in a grain storage facility consuming as much as 1.4 kg of grain each day.
- One mouse can excrete between 40 to 100 droppings per day, as well as deposit hundreds of small droplets of urine during its travels, while the rat typically produces between of 20 to 50 droppings and excretes 14 ml of urine daily.
- Rats and mice spend approximately 2% of their daily activities gnawing on various natural and man-made objects.
- The rodent's incisors grow continuously at the rate of up to 0.4 mm per day with the lower incisors growing slightly faster than the uppers. The scratch hardness of incisors measured 5.5 on Moh's scale, which is harder than iron (4.0) and several other metals.
- Rats can exert biting pressure up to 500 kg/cm2, and can bite repeatedly up to six bites per second.
- To obtain water, rats can readily gnaw through plastic water pipes and irrigation distribution systems. Through their gnawing activities, rodents can literally disassemble buildings within only few years by gnawing on the structural support timbers.
- The damage to one wire by rodents, providing it is the right wire, can have dire and expensive consequences. They can shut down entire towns and portion of cities by gnawing on the electrical components of utility stations.
- A jet was grounded for several days at an estimated loss of $100,000 per day due to an elusive rat occupying the voids of the aircraft (Hedges 1996).
- Rodents ability to start fires by carrying matches to their nest and gnaw the phosphorus or paraffin coating, causing the match burn or by causing short circuits through their gnawing of electrical wires, are commonplace.
