Rodents are a worldwide pest due to their capacity to cause structural damage, to spread life-threatening diseases, and to compete with humans for food.
|Common names:||Ship rat; Black rat; House rat; Roof rat|
|Adult Weight:||200 grams|
|Length (head + body):||150mm - 220mm|
|Length (tail):||180mm - 250mm, usually longer than head and body|
|Fur & colour:||Smoother and softer than Rattus norvegicus. Usually black or grey.|
|Ears & hearing:||Thin, translucent, large and hairless. Excellent sense of hearing.|
|Eyes & sight:||Large and prominent. Poor sight, colour blind.|
|Snout, smell and taste:||Pointed, excellent sense of smell and taste.|
|Droppings:||Scattered. Spindle or banana-shaped, about 12mm long.|
|Habits & habitat:||Non-burrowing. Nests mainly in walls, attics, vines and trees.
Active agile climber, rarely found in sewers. Rather more erratic and unpredictable in habit than Rattus norvegicus. Less wary of new objects than Rattus norvegicus. Range 30 meters.
|Feeding habits:||Omnivorous, mainly fruits, nuts, grains and vegetables. Consumes 25-30 grams per day, drinks water or eats food with high water content.|
|Life cycle:||9-12 months|
|Sexual maturity:||2-3 months|
|Litter size:||6-10 offspring|
|Maximum reproduction rate:||6 litters per year|
|Common names:||Norway rat; Common rat; Brown rat; Wharf rat; Sewer rat|
|Adult Weight:||300 grams|
|Length (head + body):||200mm - 250mm|
|Length (tail):||150mm - 200mm, shorter than head and body|
|Fur & colour:||Harsh and shaggy. Brown and black on upper head and body, grey or off white underneath.|
|Ears & hearing:||Thick, opaque, short with fine hairs. Excellent sense of hearing.|
|Eyes & sight:||Small. Poor sight, colourblind.
|Snout, smell and taste:||Blunt, excellent sense of smell and taste.|
|Droppings:||In groups, but sometimes scattered. Ellipsoidal capsule shaped, about 20mm long.|
|Habits & habitat:||Does burrow. Lives outdoors, indoors and in sewers. Nests in burrows. Can climb, though not agile. Very good swimmer. Conservative, somewhat predictable in habit. Will avoid unfamiliar objects, e.g. bait trays, placed on runs, for some days. Need to gnaw to keep their constantly growing incisor teeth worn down. Creatures of habit; will leave regular runs to & from feeding areas.|
|Feeding habits:||Omnivorous, more likely to eat meat than Rattus rattus. Consumes up to 30 grams per day, drinks water or eats food with high water content. Will hoard food for future consumption. Most likely to eat at night. Range 50 meters when looking for food.|
|Life cycle:||9-18 months|
|Sexual maturity:||2-3 months|
|Litter size:||8-10 offspring|
|Maximum reproduction rate:||7 litters per year|
|Common names:||House mouse|
|Adult Weight:||15 grams|
|Length (head + body):||60mm - 90mm|
|Length (tail):||80mm - 100mm, usually longer than the head & body|
|Fur & colour:||Brownish grey. Lighter shades occur.|
|Ears & hearing:||Large with some hairs. Excellent sense of hearing.|
|Eyes & sight:||Small, poor sight, colour blind.|
|Snout, smell and taste:||Pointed, excellent sense of smell & taste|
|Droppings:||Scattered, rod shaped, 3-6mm long|
|Habits & habitat:
||Sometimes burrows. Lives indoors & outdoors but is almost unknown in sewers. Nest generally within stored materials but may burrow. Climbs. Erratic in habit. Inquisitive towards new objects. Range 1.5 – 5 meters.|
|Feeding habits:||Nibbles. Prefers cereals. Consumes 3grams per day. Unlike rats, can survive with very little water & often obtains sufficient water in food without the need to drink.|
|Life cycle:||Span 9-12 months|
|Sexual maturity:||7 weeks. Litter size 5-6 offspring.|
|Maximum reproduction rate:||8 litters per year|
Rats live alongside man, invading his buildings and eating his food. Rats transmit disease, which are potentially fatal to man such as Weil's disease and murine typhus.
They also carry organisms which can damage man's health such as Salmonella bacteria, viruses and parasites such as nematodes and worms. Damage by rats to the fabric of buildings can be costly. Fires can easily be started after a rat has gnawed a cable. Gas and water pipes are also at risk and rat burrowing can undermine foundations and damage water courses.
Mice carry diseases such as salmonella and they can transmit a type of Leptospirosis, but not Wiel’s disease. Their continual dribble of urine contaminates food and feedstuffs. They are a particular problem in poultry units and pig housing and a very real pest in grain stores, warehouses, shops, hospitals, and domestic premises.
Faced with the increasing rodent challenge, pest controllers can no longer assume the use of even the best rodenticides in established formulations applied in long-recognised patterns will provide the required levels of control and environmental security.
As part of an integrated control approach, anticoagulants continue to provide the best and safest basis
for rodent control.
The key to their effective use, both to control rodents and to safeguard other wildlife, however, must be to deliver a lethal rodenticide dose to as many rats and mice as possible as rapidly as possible.