Pest control

Rats are between 200 and 270mm long, and the tail is 150-200mm. The fur is grey to brown with the underside white.

They are nocturnal. The main signs of an infestation are:

• droppings - slender, 15-20mm long
• gnawing marks on food packaging and building materials
• holes about 80mm in diameter in the garden or in walls and floors
• tracks about 50-70mm wide through grass in the garden
• black marks on surfaces against which the mouse has rubbed.

Rats can transfer diseases like Weil's disease and salmonellosis to people, and pollute food and water supplies with infections. They can also damage water pipes, cables and house structures by gnawing.

What can be done?

• improve hygiene - store food carefully, clear up any spilled food promptly, move rubbish and clean under work units in the kitchen where food can accumulate
• block access - ensure air bricks are properly set in place and not broken, look for holes around gas, electric and water pipes, check that doors fit correctly and fit guards around the bottoms of drainpipes
• keep yards and gardens tidy in order to eliminate nesting places. Don't put out too much food for birds and other animals. Keep waste where rats cannot reach it.

House mice are between 60 and 90mm long, and the tail is 100mm. The fur is grey or a light brown and the ears are large.

They are nocturnal. The main signs of an infestation are:

• droppings - slender, black, 3-6mm long
• gnawing marks on food packaging, cables and water pipes
• holes 20-30mm in diameter in walls and floors
• black marks on surfaces against which the mouse has rubbed.

You could see a nest, which looks like a ball of materials like paper loosely woven together.

Mice can transfer diseases like Weil's disease and salmonellosis to people, and pollute food and water supplies with infections. They can also damage water pipes, cables and house structures by gnawing.

What can be done?

• improve hygiene - store food carefully, clear up any spilled food promptly, move rubbish and clean under work units in the kitchen where food can accumulate
• block access - ensure air bricks are properly set in place and not broken, look for holes around gas, electric and water pipes, check that doors fit correctly and fit guards around the bottoms of drainpipes
• keep yards and gardens tidy in order to eliminate nesting places. Don't put out too much food for birds and other animals.
• set traps near walls where the mice run, using chocolate or biscuits as bait
• lay rodenticides in appropriate containers, out of reach of children or pets.

Wasps are up to 30mm long, with two kidney-shaped eyes, two wings folded back along the body and a striking black and yellow pattern.

A new nest is built annually from a mixture of spit and wood. If you see many wasps coming and going from one hole, crack or opening, it's likely that a nest is present. The nest looks like a grey ball, varying from the size of a golf ball to the size of a car tyre.

There is no reason to kill lone wasps, but they can cause a nuisance if they come into regular contact with people. Wasps feed on fruit and sweet food towards the end of summer.

The sting hurts but is not dangerous, but stings in the throat can lead to the toxin affecting the ability to breathe. In some cases the sting can cause anaphylactic shock; seek medical attention if you suspect someone is going into shock.

What can be done?

In order not to attract wasps into the house:

• keep waste bags and bins away from the house
• seal access points such as vents and cracks around windows and doors
• look for signs of a nest in your loft / attic from time to time over the summer
• don’t kill single wasps – this releases a chemical which attracts other wasps.

It’s not always necessary to destroy a wasps nest; you can leave it alone and it won’t develop into an infestation. Remember that wasps bring benefits by killing other insects in the garden.

A number of treatments are available to get rid of wasps. Before buying insecticides, consider:

• whether you are sure that the flies are wasps
• whether you need special clothing to prevent stinging
• how you will reach the nest
• the effect of infuriating the wasps if the treatment doesn't work.

Bed bugs are about the size of apple pips (6mm) and reddish-brown, with young bugs almost colourless. They have three pairs of hooked legs and a pair of antennae. They cannot fly.

They feed on the blood of people and some animals when they sleep. Bite clusters are red, slightly swollen and itchy. They live near their food - in headboards and seams and corners of mattresses.

You could see blood specks on bedding. This is caused by feeding or by crushing the insect.

They are not considered a significant health risk but they can cause anaemia in rare circumstances.

What can be done?

When buying second-hand furniture, check seams, cracks and crevices thoroughly for insects.

Getting rid of an infestation of bed bugs is difficult so professional help is needed.

Garden ants are seen in houses most frequently. They are a dark brown or black and about 5mm long. They follow the same path into buildings to search for food. Ants like sweet food and are usually seen in the kitchen or in food stores.

They do not pose a health risk but a large number can be a nuisance.

What can be done?

• improve hygiene - store food carefully, clear up any spilled food promptly, move rubbish and clean under work units in the kitchen where food can accumulate
• spray insecticide dust on the areas where the ants are seen, especially crevices and empty spaces
• spray insecticide aerosol on holes and crevices where ants gather or travel. Flying ants can be treated with any spray designed for flying insects.
• lay bait in gel form near tracks / crevices where the ants are seen; worker ants will carry it back to the nest and distribute it among other ants. 

Insecticides can be found in garden centres and homeware stores.

There are two main species of cockroaches in Britain:

• German cockroach - about 12mm long, yellow-brown
• oriental cockroach - about 30mm long, dark brown.

They have long antennae protruding from their heads and two pairs of wings. They are mostly found inside – in cellars, kitchens, lofts etc.

They are most frequently seen at night, scuttling across floors or up walls, and sheltering behind cupboards and near fridge and freezer motors.

Cockroaches can carry harmful bacteria onto surfaces and food.

What can be done?

• improve hygiene - store food carefully, clear food spillages quickly, move rubbish and clean under work units where food can accumulate
• block access - fill any holes around pipes and cables, seal doors and windows, cover air vents, seal internal drain covers with oil
• use residual insecticide from time to time in the areas where cockroaches hide
• use insecticide spray from time to time in the holes / crevices where cockroaches gather. Oriental cockroaches can withstand barathyroid spray under some circumstances.

Booklice are small, about 2mm long, soft and vary in colour from white to black.

They live in carpets, clothes, books and old furniture and eat mould which grows on leather, carpets, books, plaster and food in damp areas.

They pose no health risk but can damage books and spoil food.

What can be done?

• reduce humidity in the part of the house where the insects can be seen
• use insecticide

These beetles are usually a reddish brown and about 2-3mm long. They have wings and antennae.

They are frequently seen near dry foods – they like flour, bread, biscuits, cereals and other food which comes in powder form. Fully grown beetles do not eat.

The beetles spoil food and can bite through most plastic food packaging.

What can be done?

• improve hygiene - keep the kitchen and food stores clean
• use insecticide.

These beetles are usually speckled, a mixture of white, brown, black and yellow. The body is oval and about 2-4mm long. The larva is brown with white bands, covered with hair and about 5mm long.

Carpet beetles go into houses to hibernate. Whilst there they lay eggs on any furniture or materials made of animals, like leather, wool and fur.

The larvae will damage the materials on which they feed.

What can be done?

• use a vacuum cleaner on the materials where the larvae are and the surrounding area
• use insecticide.

Fully grown fleas are brown and between 1 and 4mm long, They have no wings can jump very high. You can see them in the house, on yourself or on animals. Animal fleas can bite and suck the blood of humans.

Bite marks look like spots that itch and are swollen, with a single hole in the middle. They appear in clusters or lines of two bites, and they can itch and ache for weeks.

Fleas lay oval, whitish-grey eggs on animals or on clothes, bedding or carpets. After the eggs hatch, larvae similar to maggots are formed.

If pets are scratching more than usual, check them for fleas or little black spots. On humans, it is common to see bites at the bottom of legs.

What can be done?

In order to avoid getting an infestation:

• check animals for fleas regularly; ensure that your animals are treated for fleas regularly – discuss with your vet
• check stray animals for fleas before letting them into the house 
• vacuum living spaces, furniture and areas where animals sleep regularly, and then get rid of the waste in an outside bin. Wash bedding and animal bedding frequently with hot water.
• collars to deter fleas are available from the vet.

The vet will treat animals which have fleas by spraying with insecticide.

The standard professional treatment usually means spraying all floors in a building (and perhaps soft furniture) with insecticide.

Cluster flies

• yellow cluster fly (yellow body with black marks)
• autumn fly (yellow abdomen)
• green cluster fly (bright green / blue)
• common cluster fly (brown / dark with speckled abdomen)

Cluster flies gather in buildings as the weather gets cold, swarming in roofs and lofts. They are drawn to light and windows, and begin to fly as the weather gets warmer. They do not pose a health risk.

Gnats

• housefly / lesser housefly (breed in rotting vegetables / animal droppings)
• blue fly / green fly (breed in meat)
• fruit fly (breed in rotting vegetables, soured milk, beer and vinegar)

Gnats are mostly found in buildings during summer. They will fly around a food source, where they lay eggs. They can potentially transfer bacteria / diseases to any surface or food.

What can be done?

Cluster flies: To avoid getting an infestation, you should try to block every hole near the eaves. You can use insecticide / fly strips or use citronella oil. Be careful as you treat any infestation in a loft – it’s a crime to disturb bats.

Gnats: To avoid getting an infestation, you should keep the kitchen clean and cover food. Food waste / sewage gutters should be kept clean and animal waste should be bagged before being binned. Insecticide sprays and fly strips are available.

The difference between moths and butterflies is that moths’ antennae end with a round lump. They vary from white to brown to black in colour and are attracted to electric light. One of four species of moth is usually the problem in houses – brown house moth, common clothes moth, Indian meal moth and mill moth.

They feed on cereals, clothes, leather and wool; the larva can be seen at the edges of carpets, on walls and behind furniture. They do not pose a health risk but can damage clothes, carpets, leather, fur and food.

What can be done?

• improve hygiene - clean carpets and affected materials thoroughly
• destroy the moths - you can spray flying insects insecticide at moths, and use traps and ultraviolet light to kill them. The treatment could need to be continued for over four weeks.

House dust mites are too small to see with the naked eye. They don’t bite or suck blood but some people can be allergic to them. Symptoms of allergy include sneezing, a runny or blocked nose, teary and itchy eyes, breathing problems, eczema and (in severe cases) asthma.

Other substances can cause similar allergies so medical advice should be sought in order to be able to say whether house dust mites are the problem.

What can be done?

• reduce humidity in the house by using an air conditioning system
• avoid keeping pets with feathers or fur, or keep them away from sleeping areas
• wash bedding well with warm water weekly
• vacuum carpets weekly – or choose carpetless floors.

The grey squirrel is very common. It is about 25cm long, with a tail about the same size. The underside is white; in the winter the rest of the coat is grey but it turns brown in the summer.

Squirrels are most likely to be seen during the day. They are less active in the winter but do not hibernate.

Signs that squirrels are present include:

• running noises in the attic
• damage to bird feeding equipment
• gnawing damage to roof edge and electricity wires
• insulation material pulled apart, maybe to form a nest.

What can be done?

• limit access – ensure eaves are properly sealed; block holes with a steel net, a sheet of metal or concrete. Ensure no squirrel is present before you block the hole.
• cut branches which grow too near to the roof – this is the squirrel’s path to the house
• install a cage trap – the trap should be checked daily and when a squirrel is caught, it must be killed in a humane manner, with minimal pain and fright. If a squirrel is caught, it is illegal to release it.
• use bird feeding tables which prevent squirrel access.

There are 260 species of bees in Britain and their appearance varies. You are most likely to see two types:

• bumble bee: Advice only
• honey bees: Advice only

What can be done?

To avoid attracting bees into the house:

• keep waste bags and bins away from the building
• seal access points such as vents and cracks around windows and doors
• look for signs of a nest in your loft / attic occasionally during summer.

In most cases, bees' nests do not need to be destroyed - if undisturbed, bees will not develop into an infestation.

Local beekeepers could be willing to come over and take the nest away. Visit the Welsh Beekeepers Association website: www.wbka.com

Can Gwynedd Council help?

You should not destroy bees if possible - they are an important part of local ecosystems.

Gwynedd Council pest control officers can come over to assess the problem and offer free advice.

Head lice vary in colour and are very small – young ones are about the size of a pinhead and when fully grown they are smaller than the head of a match. The main sign of lice on a head is itching. The best way of looking for lice is to use a fine comb on wet hair weekly. Seeing lice which are alive and moving is the only cause for concern.

Body lice vary in colour from orange to greyish-white and are about the same size as a sesame seed. Severe itching is the main sign of body lice. It’s usually worst around the middle, the underarms, near the bra strap or anywhere where clothes are tight. Red swellings appear on the body. Skin by the waist and groin can thicken and lose colour when lice have been there for a long time.

What can be done?

Head lice are impossible to prevent. Length nor cleanliness of hair makes no difference. They move from head to head by jumping, so they are more common among children because they hold their heads together frequently. There is no point using anti-lice solutions before the lice reach the head – this can do more bad than good.

To get rid of head lice, there are two options:

• anti-lice substances are available from the doctor or chemist
• you can use a fine comb, available from pharmacies, to check for lice and get rid of them one by one. This will need to be done every 3 days for up to three weeks in order to get rid of all the lice.

Improving personal hygiene is the best way to control and get rid of body lice. You should wash completely once a day and change clothes at least weekly. Infested clothes should be washed at a very high heat and dried in a machine on high heat. Boiling the clothes is another choice. In some cases, you should go to the doctor for further treatment.

Fully grown foxes are about 1 metre long; they have a white breast and a brownish red fur, and a long thin nose.

You could hear them making a sound similar to a baby screaming, especially in mating season, and they could disturb you by knocking bins etc while looking for food.

They dig burrows, with at least two substantial, visible holes (badger burrows have more holes). A burrow dug under a house can undermine foundations but this is uncommon. They can also seek shelter under old buildings and garden sheds.

Droppings and urine have a striking strong and musky smell, and they can soil and damage lawns as they dig for insects.

What can be done?

• improve hygiene - store food waste outside in heavy, sturdy bins with lids
• block entry - install a strong mesh cage to protect hens or pets, with about 30cm buried. Open-top cages should be at least 2 metres high, with 30cm set horizontally.
• use chemicals / supersonic sound devices / water sprays - these should keep the fox off your land but their efficiency varies.

Foxes are looking for easy food; they will eat whatever they find. Small pets are in danger so it’s important to keep them safe, but cats and dogs should be fine.

Can Gwynedd Council help?

The Council does not destroy foxes.

Officers can offer free advice on methods of dealing with this kind of animal.

Adult badgers are about 80cm from snout to tail, and their striped black and white head is recognisable.

They come out at night, and are difficult to see in the dark. They don’t usually make a noise, apart from the odd pleasurable sound and occasional barking. Signs of badgers include tracks, with 5-paw footprints, claw marks on trees, dirt pools, soil humps near entrances to sets, bedding materials and wiry hair.

They can soil and damage lawns when looking for insects and lone badgers can seek shelter under old buildings and garden sheds. They could undermine foundations by burrowing under a house but this is uncommon; they could also try to break into animal areas in order to eat them.

What can be done?

• improve hygiene - store food waste outside in heavy, sturdy bins with lids
• block entry - install a strong mesh cage to protect hens or pets, with about 30cm buried. Open-top cages should be at least 2 metres high, with 30cm set horizontally.

Badgers are protected by the Protection of Badgers Act 1992. It is a crime to:

• kill, injure, take, keep or be cruel to a badger
• damage or destroy a burrow
• prevent access to a burrow
• disturb a badger within a burrow
• persecute by other means.

Can Gwynedd Council help?

The Council does not destroy badgers - it is a crime to do so.

Officers can offer free advice on methods of dealing with this kind of animal.

Seagulls are quite large - about 55cm from beak to tail - and have a wingspan of 85cm. The wings and back are grey while the head is white. They can often be seen in town centres looking for food.

They can cause a nuisance by making noise and damaging buildings to make nests. Nests can dangerously obstruct gas boiler flumes. Droppings and feathers can block gutters, and droppings contain bacteria which cause diseases in humans. Seagulls and their young will attack people and animals that go near them.

What can be done?

• do not feed seagulls
• install bird spikes on flat roofs and roof gutter shelving to prevent birds from nesting
• install wires or nets on roofs to prevent birds from landing.

Dependent on the seagull's status, it's possible that you can disturb nesting areas, including removing nests and eggs. Generally, it's illegal to trap, injure or eliminate any wild bird, or to interfere with the nest or eggs. But there are some exemptions. Annually, the Welsh Government publishes general licences which state which bird species can be killed and how to do so.

Can Gwynedd Council help?

We do not offer a pest control service for seagulls.

Our officers can offer advice on ways to deal with birds.

Feral pigeons are grey birds, very common in town centres. They are becoming more common because:

• there are spaces for them to roost in empty buildings, bridges and structurally deficient buildings
• food is easily available - people throw fast food waste away carelessly or feed the pigeons.

The pigeons are not harmless:

• droppings are acidic and therefore damage buildings
• droppings contain bacteria which cause disease in humans
• droppings and feathers can block gutters and make paths slippery.

What can be done?

In order to control the pest:

• feed birds responsibly, by using feeding tables and equipment which hangs on a wire
• don’t put food on the floor and clear up any spilled food
• ensure that any animal food stored outside is kept in sealed containers
• ensure that food waste is kept and disposed of properly and that bin areas are kept clean and tidy.

In order to get rid of feral pigeons:

• block any gaps through which the birds could get to the roof – broken roof tiles, broken windows or eroded pointing. A professional should do this if it’s a high roof.
• install bird spikes on flat roofs and roof gutter shelving to prevent the birds from nesting.

You need a license from the police in order to shoot pigeons in populated areas.

Can Gwynedd Council help?

We do not offer a pest control service for pigeons.

Our officers can offer advice on ways to deal with birds.

UK bats are all small; they have wings of skin covered with fur or hair. Droppings are black or brown, between 4 and 8 mm long, and powder easily, in contrast to rat droppings.

They can be found in houses, churches, farms, caves, caverns and all kinds of buildings. They usually sleep upside down in crevices.

What can be done?

Bats are protected by law. It is a crime to:

• trap, injure or kill a bat
• disturb a group of bats in a way which is likely to (a) affect their ability to survive, reproduce, bring up young, hibernate or migrate, or (b) greatly affect the local population of the species
• damage or destroy spaces where bats reproduce or rest
• block a bat’s way to its resting place.

Can Gwynedd Council help?

The Council does not destroy bats - it is an offence to do so.

For advice on bats, call the UK Bats Conservation Trust on 0845 1300 228, the Countryside Council for Wales on 0845 1306 229 or your local bats / wildlife group.

If you intend to do building work on a building where there are bats, you should tell the Council’s Planning Department.

We can offer free advice on dealing with this type of pest.