1. Make sure you have an accurate identification of the rodent and a full understanding of the situation prior to selecting control measures. Different species of rodents have differing habits.
2. Read and follow instructions of bait carefully.
3. Select trap and bait which is most appropriate for the situation.
4. Place traps on or near runways only.
5. DO NOT place traps where children and animal can easily access.
6. DO NOT place traps near food, food utensils or preparation areas.
7. Make a record or map of where all bait stations have been placed, so that all bait stations are removed once control is achieved.
8. Wear gloves when handling dead rodents. Use an aerosol insecticide for the immediate area to kill the fleas which leave the dead body.
9. Carefully wash used and contaminated traps. Destroy and bait residue once control is achieved.
ABOUT RATS & MICE
There are 3 rodent pests of houses in Australia:
- The Norway rat (Ratus Norvegicus)
- The roof rat (Rattus Rattus)
- The house mouse ( Mus Musculus)
Rats and mice require food and shelter like most animals, particularly in late Autumn and Winter when they enter houses.
These conditions also accommodate their breeding. Once inside they often make their nests in walls and roofs. Rats and mice are also very good climbers and can scale rough walls, pipes, trees and vines and walk across cables.
Rats and mice are active at night and eat a wide range of food. They have a good sense of smell, taste, hearing and touch; however their sight is very poor.
They are very sensitive to all environments and move around the edges of rooms and not across them.
Rodents (especially rats) have a fear of new objects in their search for food and usually use their same tracks. This is important when baiting and trapping and it may be some days before they investigate a bait station or trap. Mice will investigate the change quicker compared to rats.
Rats and mice are commonly known for contaminating food because of the diseases they carry, which is then destroyed. This occurs at the site of harvesting, storage and manufacture, as well as in homes, restaurants and hotels. The diseases are caused from faecal, urine and fur contamination.
Rats and mice also cause damage gnawing on objects to keep their front teeth to a functional size. Things like timbers, furniture and electrical wiring have been damaged this way and in some cases resulting in house fires.
- This is the largest of the three and is a major pest in most human environments where food is found. Often present in food handling facilities, sewers, garbage areas and on most farms.
- Norway rats make burrows and have concealed escape holes known as ‘bolt holes’. During the colder months the will make their nests in walls and roof cavities.
- Norway rats weigh around 450g.
- They have a blunt nose area.
- Tail is shorter than its body length and ears are close set and small.
- Fur is coarse and brown in colour.
- It has a life span of one year and can produce five to six litters, each having six to eight young.
- The Norway rat is physically the dominant species when other rodents are present.
- Commonly found in city and suburban areas.
- Usually nest indoors, in roof and wall cavities and are good climbers.
- They prefer to eat vegetables, fruit and cereals
- Roof rat weighs around 250g.
- They have a pointed nose, large ears which are almost hairless.
- Grey, black or brown fur in colour and maybe white underneath.
- Its tail is longer than its entire body.
- It has a life span of one year and can produce four to five litters, each having six to eight young.
- The house mouse is also commonly known as the ‘field mouse’. If located outside it is a yellow-brown colour, paler than those living inside which are usually a darkish grey colour with lighter grey on belly.
- Due to being a small rodent they can easily access homes and nest in walls, cupboards and roof cavities. They have a low water requirement and feed on many foods.
- They are mainly nocturnal, but will feed during the day and are attracted to new foods quickly. Contamination of food and kitchen utensils occurs whenever mice are present. Mice can reach plague numbers on farms and properties in rural areas where they feed on stored products such as grains.
- House mouse weighs around 20g.
- They have large hairy ears and a pointed nose. Its tail is about the length of its body.
- It has a life span of one year and can produce six to ten litters, each having five to six young.
Rodents are often detected from their damage, odour or faecal droppings. The following signs should always be investigated to confirm a rat or mouse is present before baiting and trapping:
- Runways, showing up as greasy nooks on furniture and walls from rodents fur
- Urine stains on floor and cupboards
- Disappearance of food
- Sounds often at night which may include squeaking and fighting
- Nest behind cupboards and lounges made of paper and rags, sometimes snail shells
Pets often bark at other animal intruders when they are active or enter houses. Once rodent activity has been detected it is important to determine which rodent is present to determine the control.
The prevention or termination of rat and mouse infestations by simple hygiene is the most effective control procedure. Using a vacuum to reduce food particles on floors is important and must be accompanied by using sealed food containers and tight fitting lids on garbage bins. The removal of rubbish, particularly garden rubbish is also important.
Holes in walls for water and drainage pipes should be sealed to prevent rodent access. Usually cement or metal sheeting prevents rodents from entering. Inspection of the building to locate entry points is the first step in proofing.
Trapping rats and mice is often done by the home owner or pest controller. There are several types of traps from the single snap trap to multiple mouse catching devices which can hold up to 30 mice.
The single snap trap may be used with bait or set unbaited. Suitable foods include nuts, apple for baited traps. Unbaited traps have a trigger covered with fine pieces of cardboard or saw dust. They should be placed in one of the runways usually at right angles.
Because trapped rodents may exude blood, urine or faeces, traps should not be set near food preparation areas. When a rodent is caught its fleas leave the dead body and seek other hosts. It is really important to check the traps frequently and remove rodent and fleas together.
Most homeowners prefer chemical control methods, but there are situations where chemicals are not appropriate mainly for safety reasons:
- Rodents may die and decompose in hard to reach places
- Poisoned rodent may be eaten by pets
- Poisoning may not be an option for chemically sensitive people
- Trapping to eliminate the few rodents that have survived a baiting programme may be more economical.
Both single dose and multiple dose anticoagulants reduce the bloods ability to clot, causing haemorrhaging and then death. Multiple dose poisons kill rodents in four to eight days of constant feeding, while single dose poisons will kill rodents in three to seven days after only one feed.
Multiple dose anticoagulants are available as dry bait. To be effective they require continual feeding for four to ten days. It is essential that feeding and supply of bait continues for several consecutive days ensuring the build up of anticoagulants in the blood which finally causes death.
Single dose anticoagulants have the same outcome as the multiple dose, but continual feeding for several days is not necessary. Single dose anticoagulants cause death in three to seven days. These baits are available as pellets and blocks.
Both the single dose and multiple dose anticoagulants are toxic to other warm-blooded animals and so the placement of bait stations must be placed where children, pets, wildlife and livestock do not have easy access too.
In the event of accidental intake, you should refer to a GP immediately especially for children, vitamin K1 is antidote which is most effective and will most likely be given. Seek advice from your local vet for animals.