Top tips to deter pests in a heatwave - PEST UK

Providing pest control services in Berkshire, Buckinghamshire, Essex, Hampshire, Hertfordshire, Kent, London, Middlesex, Northamptonshire, Oxfordshire, Surrey, West Midlands, West Sussex, Wiltshire. Est. 1985.

Top tips to deter pests in a heatwave

In Featured, Pests

Whilst we’re experiencing a heatwave, you’ll notice an impact on the behaviour and activities of insects and other pests.

What does heat do to insects?

Insect activity is always at its highest during the summer. This is because insects are cold-blooded so their body temperature is entirely dependent on the temperature of the environment around them. Many insects thrive in the extreme heat, meaning infestations are more intense as they breed more rapidly and have a quicker lifecycle as their eggs and larvae mature faster.

During a heatwave, some of the impacts on insects include:

  • increased insect population
  • more rapid breeding
  • faster insect life cycle
  • shortened time between insect generations
  • more household infestations as insects seek protection from the sun and extreme heat indoors as well as food and moisture

What can I do to deter pests during a heatwave?

In all cases, prevention is better than cure. These are some of the ways you can reduce the stress of dealing with pests this summer.


Many ants gorging on a piece of yellow foodAnts frequently enter homes foraging for food, particularly sweet substances. Whilst they are not a risk to health, they can be present in large enough numbers to be a nuisance. They don’t deal with extreme heat and sun very well so they will enter homes for shelter from the extreme weather conditions. During hot and humid weather ants swarm to mate so that new colonies can be created.

With ants, prevention is the best method of control. Clearing up food waste straight away, including pet food debris. Food should be stored in sealed containers. If you find any entry points around doors or windows use a sealant to block them.


Flies are a nuisance. They are a hazard to human health because they transfer disease and bacteria from one source of food to another. This could be from rotting organic material or faeces before they land on your lunch. They breed and multiply even more rapidly during a heatwave which could result in a massive infestation.

Flies often lay eggs in rubbish bins, however in normal weather the bin is emptied before the eggs hatch into maggots. During very hot weather the life cycle is quicker so the eggs hatch and the maggots develop faster. Just before they’re ready to pupate they crawl away from the food they’ve been eating. This is when people are likely to notice them most. They need to be treated immediately to prevent them emerging as adult flies as they will very quickly will reproduce and become a huge infestation.

Denying flies access to your home is the best solutions. Keep doors and windows closed or install fly screens. This is especially important around kitchens and bin areas. Cover food and clear up any spillages or debris straight away, including pet food debris. Food should be stored in sealed containers.


Creating airflow in your home at night is important during a heatwave. However lights will attract biting insects.

One way to discourage mosquitoes is to put a few drops of citronella around the open window. Ensure there is no standing water near to your home as it can be a breeding area. Keep water butts covered and if you have a pond, introduce fish that will feed on any larvae.


Spiders will increase in number during the hot weather as they have more insects to feed on. As a consequence they will spin more webs to trap the insects.

If you want to stop spiders coming in through open windows put a few drops of peppermint oil around the opening.

Wasps, bees and hornets

Hornets are becoming more common in the UK because of the increased temperatures. A heatwave will encourage them to breed and we’ll see more of them.

Pests in SeptemberPeople notice wasps more during the summer as they spend more time outside. During a heatwave, both wasps and bees need water to cool their nests by evaporation so you may see them taking water from ponds or bird baths.

We recommend checking for wasp nests in lofts, gardens, sheds and under the eaves. If you check during spring, the nests will be smaller with fewer wasps and will be easier to treat. In summer if you notice wasps randomly appearing within your home this can be a sign of a wasp nest in the loft. Keep doors and windows shut as much as possible to prevent wasps entering.


Rats, mice and glis glis may also seek shelter from the sun and heat in your home. Once there they’ll make themselves comfortable, building nests and helping themselves to your food or eating their way through electrical wiring and plaster or worse.

It’s easier to take precautions to deter rodents from entering your home. Block any entry points around doors or windows and under eaves.

Is it safe to use insecticide sprays?

Be careful when you use an insecticide spray as it can lead to serious health issues for you and your family, your pets. It can even cause damage to your property if you use it incorrectly.

If you have an infestation that you need help with, call Pest UK and one of our technicians will come and inspect your property, find the source of the infestation and apply the appropriate treatment, safely and effectively.

Click here for our full price list


Top tips to get rid of fruit flies »
Fleas in the office are a common problem | How to get rid of fleas from an office «