What is vermin?

Vermin is the general term applied to animal and bird species regarded as pests, and especially to those associated with diseases. Certain parts of schools, for example, kitchens, food stores and dining halls can provide ideal conditions for certain pests and vermin. 

Vermin and pests in schools

Ants

The commonest species of ant is the black garden ant. A highly organised and social insect, a colony will nest and include worker ants which are attracted to sweet food.

Ants may cause contamination to food and preparation areas. Limited measures can be taken by facilities staff but professional pest control contractors should be brought in if large numbers of ants’ nests are found.

Bats

Bats may only be handled by those licensed to do so. They cause no direct harm though their droppings may cause problems with smell and insect infestations.

European bat lyssavirus (EBL) is a rabies-like virus which infects insectivorous bats in Europe. It is very rare (only six confirmed cases identified in the UK). Anyone exposed to EBL and given prompt treatment (immunisation and immunoglobin) will not develop the infection.

The Wildlife and Countryside Act 1981 provides protection for all species of bat found in the UK. It is illegal to kill, or even disturb, bats in their roosts.

If bats are found on or near school premises, the local environmental health officer should be contacted. The Bat Conservation Trust can be contacted if help is needed to remove injured or dead bats.

Wasps, bees and hornets

Wasp nests are normally built in sheltered spots, with easy access to outside. They can be found in areas such as wall cavities, roof spaces and under eaves. They can grow to around the size of a football as the summer progresses. Only female wasps sting, but they can do so repeatedly.

Honey bees live in colonies often greater than 30,000 in roof and wall cavities, and hollow trees. They swarm in early summer. They have a barbed sting and die once this is used but will sting when provoked.

Untreated infestations can cause contamination of food, harm to mortar and building fabric, and threats of stings. Some people may experience anaphylactic shock on being stung and will require prompt treatment. (See the NEU briefing Anaphylaxis in Schools, on the union website at: neu.org.uk)

Professional vermin control contractors should be contacted to rid a school of wasp or hornet infestation. If there is an issue with bees, a local beekeeper should be contacted to relocate, but never destroy, the nest as they are a protected species – go to: bbka.org.uk/find-beekeeping-near-you

Bird mites

Bird mite infestations in schools are rare but more likely to occur during late spring to early summer.

Problems can arise from mites from abandoned birds’ nests finding their way into buildings and feeding upon humans once the bird host is no longer a source of food.

The mites are good at surviving in a human environment, by biting people, when the original avian host has gone – although they can’t survive in the long term without a bird host. A mature bird mite is only about 0.5 mm or less, and the immature mite is even smaller.  Bird mites do not fly, however they are small and aggressive and, when a host is detected, they can float down from the ceiling and other places to land on the individual. If staff and children end up transferring mites from the school to their home, the problems will be compounded.

Symptoms include:

  • pinprick bites with or without lesions
  • frequently intense itching of the skin
  • vague sensation of crawling on the skin
  • bite marks and lesions that heal very slowly.

Bird mites can be an extremely difficult problem to eradicate even for commercial pest control companies, as they are an unusual infestation, and a specialist firm with experience in this area may be required. The local authority’s environmental health department and the health and safety officer need to be informed, and they should be able to recommend an approved specialist company to undertake the eradication.

All potential original sources of the infestation need to be checked and cleared, for example, removal of abandoned bird nests in the roof space, and all entry points for birds should be sealed off to prevent future roosting. This in itself may not be enough as the mites can get everywhere, including in carpets, clothing, curtains, walls, ceilings, cracks and crevices.

Teachers need to consider the potential risk of introducing bird mites to the classroom when using bird nests for display purposes on nature tables or for science lessons.

Schools are very cluttered places, so it is possible that in order to properly address an infestation, the school may need to be closed, rather than a piecemeal approach being adopted, with a few classrooms at a time being closed for fumigation. A piecemeal approach also raises the issue of powerful chemicals being used in close proximity to staff and pupils, and whether this could cause health problems, especially for vulnerable groups. Staff with particular concerns over pregnancy or possible effects on babies/young children should consult their GP.

Ticks

Ticks are small, blood-sucking arthropods, which are present throughout the UK. They prefer moist, shady areas such as grass and bushes, and least prefer dry areas, but they can survive in many places including parks and gardens. Ticks attach themselves to animals to feed, and will also attach themselves to humans by transferring from vegetation.

Ticks are carriers of a disease known as Lyme disease, which if untreated, can lead to serious illness. While not all ticks carry the disease, and not all tick bites will result in infection, it is important to take necessary precautions to prevent tick bites where possible, and to check for ticks after spending time outdoors, as the longer a tick is attached, the higher the risk of infection.

Ticks are small, and their bite is normally painless, so a person will not necessarily know they have been bitten without checking carefully for any ticks. Lyme Disease Action advises individuals to check themselves for ticks immediately after visiting a place where ticks may have been present, and for three days after.

Ways to minimise the risk of tick bites include:

  • wearing shoes rather than sandals and tucking trousers into socks
  • wearing light coloured clothing which makes ticks more visible
  • walking in the middle of paths rather than at the edges closer to vegetation
  • checking yourself after sitting on logs or against tree trunks
  • spraying clothing with anti-tick pesticide.

If a tick is found, it should be removed immediately, ideally with a tick removal tool. The tool allows all parts of the tick to be removed, and prevents it releasing additional saliva into the wound which could contain bacteria. Once the tick has been removed, antiseptic should be applied to the bite area. Tick removal tools can be purchased at a small cost from vets and pet shops or from the Lyme Disease Action.

The NEU recommends that schools have a tick removal tool on site, and a tool is carried whenever outdoor activities and trips are organised. Lyme Disease Action has advice on how to remove ticks if a specialist tool is not available.

Schools, especially if organising outdoor activities, should advise children how to avoid ticks wherever possible, and to check themselves for any ticks after the event. Advice should also be given to parents if outdoor activities are undertaken, in order that they can check their children for ticks, and are aware of the symptoms associated with Lyme disease, should a bite occur. Young children are more commonly bitten on the head or scalp, so they should be checked around the neck, behind the ears and along the hairline.

Lyme disease is most effectively treated with early diagnosis. Around two-thirds of people who contract Lyme disease will develop a rash, up to four weeks after the bite, often called a ‘bull’s eye rash’ as it is most commonly a circular red rash that spreads outwards.

Other symptoms in adults include flu-like symptoms such as aching, fever and headache, fatigue and joint pain. In children, facial palsy (weakness or paralysis on one side of the face) with headache and fever can be symptomatic of Lyme disease. If any of these symptoms are experienced, medical advice should be sought as soon as possible. Lyme disease can be difficult to diagnose, so it is important to inform the GP if a tick bite has taken place, or is suspected, in order that a correct diagnosis can be made.

Cockroaches

There are two types of cockroach found in the UK – the Oriental cockroach and the German cockroach.

Cockroaches will feed on almost anything, from food to faecal matter. They are commonly found in kitchens and heating systems. They prefer warm moist conditions and they reproduce rapidly; a German cockroach can produce up to 240 eggs per month.

They can spread bacteria and usually indicate that food preparation areas are not clean. Germs can be spread from the body of a cockroach or from their droppings. They can carry dysentery, gastro-enteritis, typhoid and food poisoning organisms. Contamination occurs when the cockroaches come into contact with food.

Fleas

Fleas are external parasites, living off the blood of mammals and birds, and include cat/dog fleas, human fleas and rat fleas.

Beside the problems posed by the flea itself, they can also act as a vector for disease, for example, they can transmit a variety of viral and bacterial diseases to humans and other animals.

Fleas have helped cause epidemics by transmitting diseases such as the bubonic plague between rodents and humans by carrying bacteria.

In the UK, human fleas are rarely a problem (and can be cured by removal of infested clothing) but cat/dog fleas may cause considerable nuisance. A few adult fleas live on the animal host, while hundreds of eggs and larvae contaminate the pet’s bedding and favourite resting places. The eggs are just visible to the naked eye as small pearly white round objects. Adult fleas require blood meals to survive (and the female needs a blood meal for her eggs) but can survive months without a feed. Cat/dog fleas are not thought to transmit any serious illness to humans but they can cause severe irritation.

Mice

‘House’ mice nest in the ground or in any protected location in nests constructed of shredded fibrous material such as paper. The female produces five to ten litters per year, averaging five per litter.

Mice contaminate food with their urine, droppings and hair, and among the diseases they may transmit to humans are:

  • salmonellosis (food poisoning)
  • rickettsialpox
  • lympocytic choriomeningitis.

Mice also chew cables and wiring, and this can cause short-circuiting and increase fire hazard.

Pigeons

Descended originally from the wild rock dove (a cliff-face dweller), pigeons have adapted to urban environments and lack natural predators.

Pigeons can carry psittacosis, which can cause respiratory illnesses and flu-like symptoms if humans are exposed to infected birds. Local authorities are empowered to control pigeons if they pose a threat to public health.

Rats

Common rats live in any situation that provides food, water and shelter. The common rat is the most widespread of its species and is widely found in urban and rural areas. In homes they will live in loft spaces, wall cavities, cellars or under floorboards; in gardens, they will burrow into compost heaps and grassy banks or under sheds. They are also commonly found living in sewer systems and rivers. Rats will eat or contaminate food intended for humans. It is estimated that up to five per cent of food produced worldwide is lost as a result of rodent activity.

Their favourite foods are cereal products, although they will eat almost anything that humans eat.

Rats can transmit several diseases to humans including Weil’s disease, a bacterial infection that attacks the kidneys and liver, and can be deadly. It can be contracted after swimming in rivers or lakes as it is spread by rat urine found in river water and banks. It can be transmitted through cuts and scratches or the lining of the mouth, throat or eyes, after contact with infected rat urine or contaminated water.

Cases of Weil’s disease have been increasing in recent years, linked to winter flooding of the rats’ habitats, followed by high summer temperatures. Teachers organising visits to places where there is a risk of transmission from contaminated water need to be aware of this and include it in their risk assessment.

Squirrels

Grey squirrels were introduced in this country during the nineteenth century; they now occupy most of the mainland of England and Wales. They are resident in woodland as well as urban parks and gardens.

The main threat from squirrels is that they enter roof spaces and chew woodwork, strip insulation from wiring and water pipes, and drown in open water tanks causing contamination.

Preventative measures should also be taken such as blocking gaps and entry holes and ensuring frequent inspection of roof spaces.

Foxes

Foxes are increasingly seen in urban and suburban areas as well as rural areas. The fox is primarily carnivorous and they are highly effective scavengers, finding waste in towns and cities plentiful. The law prevents the use of poisons or illegal traps or snares to control foxes, and it is illegal to shoot them in urban areas.

Foxes can carry toxocariasis, a parasitic roundworm which can be passed to humans. Infection is extremely rare and only affects around two people per million in the UK each year. Fox faeces may contain bacteria which can cause sickness in humans, so faeces should not be directly handled.

Fox dens are established in January/February for cubs born in March. If a fox den is discovered in school grounds, the environmental health officer should be contacted for advice.

Control measures

Schools should have policies on pest control containing the following control measures:

  • stop pests getting in with well-fitted doors, covered drains or fly screens
  • look out for the evidence of the presence of pests including droppings, chew marks on carpets and wiring, insect droppings and nests
  • a named member of staff should take on the role of pest control monitoring and liaise with the local authority environmental health officer
  • adequate cleaning measures should be in place to avoid build-up of animal and bird droppings which can be harmful to health.

Pest control companies

The British Pest Control Association is the UK trade association representing the industry. The association represents the industry to Government and has an established code of conduct and professional standards by which all members must conform. Their website – bpca.org.uk – provides some useful background information.

Any reputable pest control firm will be able to eradicate pests/vermin and ensure that premises are clean and safe for re-occupation. The contractors will also ensure that any pesticides or other toxins used to eradicate infestation are safely administered without risk to users of the building.

Checklist for representatives

  1. Ensure that there is a policy to deal with pest or vermin infestation in the school with details of the named member of staff responsible for pest control and the environmental health officer at the local authority.
  2. Elimination of infestation generally requires the employment of a specialist pest control contractor.

If an infestation is discovered:

  • the affected areas should be closed pending the arrival of the local authority environmental health team member
  • no food or drink should be prepared, nor should pupils and staff re-occupy the space, until the pests have been eliminated, disposed of and the area thoroughly cleaned.