Mice are a problem in buildings because they live indoors. They are more liable to cause fires by gnawing cables and they can damage insulation in animal housing causing costly heat loss and expensive replacement.
Mice carry diseases such as Salmonella and they can also transmit a type of Leptospirosis, but not Weil'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 even domestic premises.
Being so small they are very easily carried, unnoticed, in egg boxes, food packaging, laundry baskets, etc. Entering a new location through gaps as small as 6mm, mice build nests which are hard to find, populating an area with new colonies quickly with devastating effect. Because mice can reach sexual maturity 42 days after birth, populations grow much faster than those of rats, which take about twice the time to reach maturity.
The difficulty of preventing access, coupled with the rapid population growth and natural dispersal of mice, means that a large building may contain a number of colonies, each of which must be treated as a separate infestation and control needs to be tackled systematically.
Common Names: House mouse Adult Weight: 15 grams Length (head + body): 60-90mm Length (tail): 80-100mm, usually longer than head and 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 and taste. Droppings: Scattered. Rod shaped, 3-6mm long. Habits, habitat: Sometimes burrows. Lives indoors and ourdoors but is almost unknown in sewers. Nests generally within stored materials but may burrow. Climbs. Erratic in habit. Inquisitive towards new objects. Range 1.5-5 metres. Feeding habits: Nibbles. Prefers cereals. Consumes 3 grams per day. Unlike rats, can survive with very little water and often obtains sufficient water in food without the need to drink. Life cycle: Span: 9-12 months. Sexual maturity: 6 weeks. Litter size: 5-6 offspring. Maximum reproduction rate: 8 litters per year.