Rats and Mice
Rats and Mice
Rats and mice can be a problem in urban, suburban and rural areas. They infest old buildings and crowded, unsanitary areas that exist in an urban environment. However, they can also be a problem even where newer homes and sanitary conditions exist. Since these rodents eat practically anything humans eat, they get plenty of food from home gardens, fruit or nut trees and even parts of some ornamental shrubs and flowers.
There are six major problems caused by rats and mice:
- They eat food and contaminate it with urine and excrement.
- They gnaw into materials such as paper, books, wood or upholstery which they use as nest material. They also gnaw plastic, cinder blocks, soft metals such as lead and aluminium, and wiring which may cause a fire hazard.
- Rats occasionally bite people and may kill small animals.
- They spread many diseases.
- Rats can damage plants and eat garden vegetables.
- Rats and mice are socially unacceptable.
Mouse or Rat?
A female rat life span averages about a year in the wild. They can burrow long distances from nest to food sources, reducing their exposure to predators. The tunnels may extend four vertical feet into the earth. They can scale walls and walk across telephone wires with ease. They are excellent swimmers--capable of navigating a half mile through open water. They are amazingly resilient, easily surviving falls up to 50 feet.
There are two primary species of rats present in the UK:
The Norway Rat is 13-18 inches total length, with a short tail. It is mostly brown, with a lighter coloured stomach. The tail is semi-naked and darker above than below. Norway rats build their nests in burrows under buildings, low shrubs or ground cover, wood piles, yard accumulations of junk and garbage dumps.
The Ship Rat is also 13-18 inches total length, with a longer tail. It is mostly black with some grey below, although there are some variations. The tail is also semi-naked, but of one colour. The Ship Rat is a better climber than the Norway rat and is more likely to build its nest in walls, attics, vines or trees. The Ship Rat is now very rare.
Mice
We also have two species of mice that cause problems. The House Mouse and the Wood Mouse.
The House mouse looks somewhat like a young ship rat, but smaller. It is approximately 5 to 7 inches total length. Like the roof rat, its tail is very long but mice have proportionately smaller heads and feet. The colour of the house mouse depends upon its habitat; if it lives indoors it will usually be dark grey with a light grey stomach; outdoors it will usually be a sandy brown colour. House mice do not pose as serious a problem to the householder as rats, but they can be quite a nuisance. They also eat and contaminate food with their urine and droppings; may gnaw on wiring creating a fire hazard, and they can transmit some diseases.
Wood Mice have dark brown fur with enormous eyes and ears for their size. They grow to about four inches long. They are generally nocturnal animals with superb hearing and vision.
The Wood Mouse will live just about anywhere there is food and shelter. It traditionally roams fields, hedgerows, forests and grass lands where it can find plenty of food. They will eat a range of seeds, berries, worms, carrion and other similar food. It tends to have a short life in the wild as so many different creatures prey on them, with an average age between 6 and 12 months, although they live longer in captivity and when conditions are favourable.
They nest wherever there is cover and warmth, this usually means below ground but they can also be found in hedgerows, buildings, car radiators and other similar dwellings.
Rodent Control
The most important steps in controlling rodents involve sanitation and elimination of their home sites.
Sanitation
- Store rubbish in rodent-proof containers. Make sure your bins have tight fitting lids so dogs or wildlife can't tip them.
- Store pet food in rodent-proof containers. Clean up spilled or unused pet food. Also, clean up pet excrement, as rats will eat it if they have to.
- Do not scatter food for wildlife. Use rodent-proof bird feeders. If rats are a serious problem, eliminate all bird feeders.
- Compost piles should be properly managed to ensure rapid decomposition of potential rat foods.
- Clean up fallen fruits or nuts from trees. Prune seed pods from lilac and other shrubs.
- Store garden/lawn seed and bone meal in rodent-proof containers.
Eliminate shelters
- Employ rodent-proofing features in new buildings.
- To rodent-proof existing buildings, you should:
- repair any cracks or small holes in the foundations, repair broken windows and doors and sewers
- seal any holes, where pipes or wires enter the building, with sheet metal collars or concrete.
- repair screens and cover foundation vents with rodent proof screen material.
- Lift compost, lumber and wood piles at least 12 inches above ground.
- Remove unmanaged blackberries or brush near buildings.
- Prune ornamental shrubs away from the ground and avoid planting ground covers that afford shelter (ivy).
Population Control
Choosing between traps and poison for rodent control will depend upon the severity of the problem, the location and the experience of the householder.
Traps are often preferred over poison baits for the following reasons:
- Poison baits, carelessly used, can harm children, pets and non-target animals.
- Sick rodents may escape to areas between walls or under floors where they die and decompose, causing odour and insect problems.
- Traps are often especially preferred for controlling easy-to-trap mice, since they eat less than rats and sometimes do not ingest enough foeticide to make it effective.
Snap traps are recommended and should be placed in areas that are frequented by rodents. These areas can be identified by looking for gnaw marks, rodent tracks, droppings, urine stains, burrows or grease smudges along walls. An effective method of baiting snap traps is to bind a small wad of gauze into the trigger with thread and then work peanut butter into the gauze until saturated. The gauze acts to entangle the rodent's teeth so they can't escape before tripping the trap mechanism. Set the trap AFTER you place the bait on the trigger!
Rat traps should be baited and left UNSET until rodents begin feeding. This will help ensure success. Traps should be tied down or anchored in some way, as rats may drag the trap away if they are only partially (non-fatally) caught.
Gum drops, bacon, nuts, oats and dried fruit may be used in addition to peanut butter for bait. When trapping mice, make the bait in each trap about pea-size and attach it to the tripping mechanism with thread or thin wire if necessary. Traps should be baited with fresh material regularly to remain attractive to the pests. There should be many more traps than rodents for trapping to be effective. It is best to place traps close to each other (every 5 - 10 feet for mice - no more than 20 feet for rats) and move them every few days if no rodents are caught. Be aware, though, that older rats MAY avoid a newly placed trap for over a week so, for rats, you may want to leave traps in place for two weeks before trying another place. Success is enhanced by placing traps with the trigger-end against walls where the rodents like to run. This allows the pests to run across the trigger from both directions. Traps can be reused without special cleaning.
Rodenticide Baits
Always read the label before using any pesticide! There are many rodent baits available on the market. These are usually ready-to-use baits containing an anticoagulant poison. When using rodent baits, they should be kept out of reach of children, pets and wildlife. The best way to make them inaccessible is to use well-constructed bait boxes with two access openings, just large enough to admit rats or mice (about two inches).
Follow the directions on the label for the correct dosage.
If poisons are used, eliminate all other food sources, such as rubbish, dog food, fallen fruit, compost and dog mess.
Professional pest control operators also handle baiting or trapping programmes.
Rats and Mice
Rats and Mice
Rats and mice can be a problem in urban, suburban and rural areas. They infest old buildings and crowded, unsanitary areas that exist in an urban environment. However, they can also be a problem even where newer homes and sanitary conditions exist. Since these rodents eat practically anything humans eat, they get plenty of food from home gardens, fruit or nut trees and even parts of some ornamental shrubs and flowers.
There are six major problems caused by rats and mice:
- They eat food and contaminate it with urine and excrement.
- They gnaw into materials such as paper, books, wood or upholstery which they use as nest material. They also gnaw plastic, cinder blocks, soft metals such as lead and aluminium, and wiring which may cause a fire hazard.
- Rats occasionally bite people and may kill small animals.
- They spread many diseases.
- Rats can damage plants and eat garden vegetables.
- Rats and mice are socially unacceptable.
Mouse or Rat?
A female rat life span averages about a year in the wild. They can burrow long distances from nest to food sources, reducing their exposure to predators. The tunnels may extend four vertical feet into the earth. They can scale walls and walk across telephone wires with ease. They are excellent swimmers--capable of navigating a half mile through open water. They are amazingly resilient, easily surviving falls up to 50 feet.
There are two primary species of rats present in the UK:
The Norway Rat is 13-18 inches total length, with a short tail. It is mostly brown, with a lighter coloured stomach. The tail is semi-naked and darker above than below. Norway rats build their nests in burrows under buildings, low shrubs or ground cover, wood piles, yard accumulations of junk and garbage dumps.
The Ship Rat is also 13-18 inches total length, with a longer tail. It is mostly black with some grey below, although there are some variations. The tail is also semi-naked, but of one colour. The Ship Rat is a better climber than the Norway rat and is more likely to build its nest in walls, attics, vines or trees. The Ship Rat is now very rare.
Mice
We also have two species of mice that cause problems. The House Mouse and the Wood Mouse.
The House mouse looks somewhat like a young ship rat, but smaller. It is approximately 5 to 7 inches total length. Like the roof rat, its tail is very long but mice have proportionately smaller heads and feet. The colour of the house mouse depends upon its habitat; if it lives indoors it will usually be dark grey with a light grey stomach; outdoors it will usually be a sandy brown colour. House mice do not pose as serious a problem to the householder as rats, but they can be quite a nuisance. They also eat and contaminate food with their urine and droppings; may gnaw on wiring creating a fire hazard, and they can transmit some diseases.
Wood Mice have dark brown fur with enormous eyes and ears for their size. They grow to about four inches long. They are generally nocturnal animals with superb hearing and vision.
The Wood Mouse will live just about anywhere there is food and shelter. It traditionally roams fields, hedgerows, forests and grass lands where it can find plenty of food. They will eat a range of seeds, berries, worms, carrion and other similar food. It tends to have a short life in the wild as so many different creatures prey on them, with an average age between 6 and 12 months, although they live longer in captivity and when conditions are favourable.
They nest wherever there is cover and warmth, this usually means below ground but they can also be found in hedgerows, buildings, car radiators and other similar dwellings.
Rodent Control
The most important steps in controlling rodents involve sanitation and elimination of their home sites.
Sanitation
- Store rubbish in rodent-proof containers. Make sure your bins have tight fitting lids so dogs or wildlife can't tip them.
- Store pet food in rodent-proof containers. Clean up spilled or unused pet food. Also, clean up pet excrement, as rats will eat it if they have to.
- Do not scatter food for wildlife. Use rodent-proof bird feeders. If rats are a serious problem, eliminate all bird feeders.
- Compost piles should be properly managed to ensure rapid decomposition of potential rat foods.
- Clean up fallen fruits or nuts from trees. Prune seed pods from lilac and other shrubs.
- Store garden/lawn seed and bone meal in rodent-proof containers.
Eliminate shelters
- Employ rodent-proofing features in new buildings.
- To rodent-proof existing buildings, you should:
- repair any cracks or small holes in the foundations, repair broken windows and doors and sewers
- seal any holes, where pipes or wires enter the building, with sheet metal collars or concrete.
- repair screens and cover foundation vents with rodent proof screen material.
- Lift compost, lumber and wood piles at least 12 inches above ground.
- Remove unmanaged blackberries or brush near buildings.
- Prune ornamental shrubs away from the ground and avoid planting ground covers that afford shelter (ivy).
Population Control
Choosing between traps and poison for rodent control will depend upon the severity of the problem, the location and the experience of the householder.
Traps are often preferred over poison baits for the following reasons:
- Poison baits, carelessly used, can harm children, pets and non-target animals.
- Sick rodents may escape to areas between walls or under floors where they die and decompose, causing odour and insect problems.
- Traps are often especially preferred for controlling easy-to-trap mice, since they eat less than rats and sometimes do not ingest enough foeticide to make it effective.
Snap traps are recommended and should be placed in areas that are frequented by rodents. These areas can be identified by looking for gnaw marks, rodent tracks, droppings, urine stains, burrows or grease smudges along walls. An effective method of baiting snap traps is to bind a small wad of gauze into the trigger with thread and then work peanut butter into the gauze until saturated. The gauze acts to entangle the rodent's teeth so they can't escape before tripping the trap mechanism. Set the trap AFTER you place the bait on the trigger!
Rat traps should be baited and left UNSET until rodents begin feeding. This will help ensure success. Traps should be tied down or anchored in some way, as rats may drag the trap away if they are only partially (non-fatally) caught.
Gum drops, bacon, nuts, oats and dried fruit may be used in addition to peanut butter for bait. When trapping mice, make the bait in each trap about pea-size and attach it to the tripping mechanism with thread or thin wire if necessary. Traps should be baited with fresh material regularly to remain attractive to the pests. There should be many more traps than rodents for trapping to be effective. It is best to place traps close to each other (every 5 - 10 feet for mice - no more than 20 feet for rats) and move them every few days if no rodents are caught. Be aware, though, that older rats MAY avoid a newly placed trap for over a week so, for rats, you may want to leave traps in place for two weeks before trying another place. Success is enhanced by placing traps with the trigger-end against walls where the rodents like to run. This allows the pests to run across the trigger from both directions. Traps can be reused without special cleaning.
Rodenticide Baits
Always read the label before using any pesticide! There are many rodent baits available on the market. These are usually ready-to-use baits containing an anticoagulant poison. When using rodent baits, they should be kept out of reach of children, pets and wildlife. The best way to make them inaccessible is to use well-constructed bait boxes with two access openings, just large enough to admit rats or mice (about two inches).
Follow the directions on the label for the correct dosage.
If poisons are used, eliminate all other food sources, such as rubbish, dog food, fallen fruit, compost and dog mess.
Professional pest control operators also handle baiting or trapping programmes.