During the cooler months of the year both rats and mice move closer to or into buildings so that they are more often seen by people.
To discourage or get rid of rats and mice you need to attack the problem on three fronts:
1. Clean up.
2. Keep them out.
3. Wipe them out.
1. Clean up inside. Old newspapers or magazines, boxes, old cloths and rubbish in cupboards, spare rooms and basements provide ideal nesting places for rodents especially mice. In kitchens, pay particular attention to any neglected corners.
2. Clean up outside. Piles of bricks, timber, rubble, old cars or appliances, heaps of garden rubbish can all be used by rats and mice for nesting.
3. Make sure that rubbish bins have tight fitting lids and that they are always kept on.
4. Fix dripping taps and do not let water collect in buckets or tins outside. These are all sources of drinking water for rodents.
5. Do not leave food for pets or birds out overnight where rats can get at it.
Keep them out
Rats and mice are very mobile and can enter buildings in all sorts of ways. They can climb vertical surfaces and gnaw through walls and gaps around windows and doors. Mice need a hole only 6mm wide while a rat can squeeze through a hole not much bigger. They are also good swimmers and use waterways and sewers.
1. Seal holes around pipes into buildings with cement or metal sheathing.
2. Make sure that doors and windows fit tightly and repair any damage.
3. Cover all holes and gaps into basements and houses with fine wire mesh.
Wipe them out
Poison and traps are the most effective ways of killing rats and mice.
The use of poison bait is the most effective method of rodent control. With all baits follow the instructions on the pack carefully and remember:
1. Keep pets and children out of danger by putting bait inside a bait station or some other protected site.
2. Use fresh bait and protect it from the weather.
The Brown Rat generally nests outdoors in burrows dug under the floors of houses, sheds or other buildings, in banks, in piles of rubble or in rubbish heaps, compost heaps or refuse tips.
During the day rats usually stay in their burrows and come out a night to search for food.
They eat meats, fish, flour, seeds, grains, fruits, vegetables and anything a human will eat. They eat 30g of food per day and drink about 15ml water each day. A rat must have water daily to survive.
The brown rat is greyish-brown in colour but this varies from pure grey to pure black or any combination of this. They are large and stocky, measure 30-45 cm in length including the tail. They have a blunt nose, small close-set ears and a long naked tail. They weigh up to 650g. The rat dropping is 19mm long and oblong shaped.
Brown rats live in small, hierarchical family groups, including one or more dominant male. The dominant males territory extends up to about 100m and is explored daily, any intruders being ejected often after a fierce, sometimes fatal fight. They are neo-phobic (showing a fear of new objects) which makes them cautious and any new object in their territory takes them several days before they will accept it. Like mice, rats are colour blind and have poor eyesight. Their sense of smell and touch is however acute.
Rats can squeeze through a hole of 13mm diameter. Though not good climbers because of their bulk, the brown rat can climb up the inside and outside of pipes and jump as much as a metre vertically, drop 15cms without injury and can burrow down to a depth of 1.2 m.
Brown rats are capable of mating at three months. Females come into heat every 4 or 5 days. Females have an average of 3 – 7 litters per year with 6 – 12 pups per litter. Their eyes open at 6 days and they are fully furred by 15 days. After giving birth the female goes back into heat in 24 hours. Adults live for approximately one year. Brown rats have 6 pairs of nipples.
Signs of Rats in and around your structure.
- Droppings, which are soft when fresh, along well-travelled pathways, in feeding areas and near the rodent’s shelter.
- Tracks, including footprints and tail marks, on dusty surfaces, in mud and snow.
- Urine along travelled paths or in feeding areas. Both wet and dry rodent urine will glow under ultraviolet light (black light).
- Smudge or rub marks on beams, rafters, walls, pipes and other fixtures.
- Gnawing marks on doors or ledges, in corners, in wall material, on stored material or on other surfaces.
- Noises in the walls caused by gnawing, climbing, clawing, squeaks and fighting, particularly at night when rodents are most active.