In an urban setting, rodent refer to the commensally brown rat (or sewer rat, Rattus Norvegicus), the roof rat (Rattus rattus) and the house mouse (Mus musculus). Given ideal conditions, one pair of rodent can produce up to 2,000 offspring in only one year.Their high agility enables a young mouse to enter a building through a 1 cm sq. gap with great ease. They are disease-carrying pests because they live and breed in highly unhygienic places e.g. sewers and garbage dumps and hence pose a threat to our health. Diseases like jaundice, Weil’s disease, the well known plague and the lesser–known hanta viral infections with influenza-type symptoms are associated with rodents. What is not widely known are the fire-hazards they cause when sharpening their chisel–like tooth on electrical wirings and insulations.
Sighting of the nocturnal creatures in the day signals heavy infestation simply because they are acting against their nature to forage for food when their enemies, especially people, are most active.
Tell-tale signs of invasion are their droppings (a rat produces about 50 droppings within 24 hours), odor of urine, and damage to packaging especially food, gnaw marks, smear marks and burrow tracks.
RECOMMENDATION FOR THE RESTRICTION OF RODENTS
The first requirement is attention to the area surrounding the building. Piles of rubbish, timber or other materials should not be allowed to accumulate. Redundant equipment should be removed or properly stored. Items such as pallets will harbor rodent if not adequately stacked and the area inspected.
Rodents often gain access to cavities through cables or pipe holes which have not been sealed, or through air-bricks or ventilator grilles. Entry to the inside of the building is often accomplished by these means, and mice can squeeze through a ½” gap with ease. Thus to minimize the risk of rodent entry, all doors should have a working clearance of no more than 1/8”.
External pipes require “back inlet gullies” at the ground level where they drain water, of wire-mesh where they act as ventilation pipes.
Internal pipes and cables can allow access unless they are tightly sealed where they pass through walls, floors or ceilings and special attention must be given to vertical ducts which allow free movement by rats and mice from one floor of the building to the next.
CONTROLThe first line of defense against rodent invasion includes proper sanitation to limit the pest food and water; practicing good housekeeping to minimize harborages and breeding sites; proper maintenance and more importantly, exclusion measures to prevent them from getting in.
After consuming the right quantity of baits, the rodent would die from internal hemorrhaging in about a few days to a week. The delayed killing action has the advantage that the rodent would not develop any “bait shyness“. Besides giving a greater margin of safety against accidental poisoning – antidote being Vit. K1; the rodenticides are effective against warfarin resistance rats (warfarin being the active ingredient in most rodenticides found on the market shelves).