5 common household pests to watch out for this winter

While a lot of pest infestations peak in the summer, winter can mean uninvited guests head indoors to seek warmth and food – or become active again once the heating is turned on.

We've listed the creatures to look out for this winter – from mice and woodlice to bedbugs and woodworm – and tell you how to stop a minor pest issue from becoming a full-blown infestation.

1. Mice and rats

While mice and rats can appear all year round, the colder winter weather means they're more likely to venture into your home looking for warmth, food and shelter. In doing so, they can cause damage by chewing through pipes, walls or electrical wires. They can also sniff out food and are capable of chewing through packaging to reach it.

Aside from physical damage, you might notice other common signs of rodents, such as grease marks, droppings or a strong urine smell.

If you've spotted a rat or mouse, you might be tempted to lay down traps or poison. We run through the pros and cons of different methods in our guide to getting rid of mice in your home.

How to prevent mice and rats this winter

• Block holes where they could be gaining access Mice can squeeze through gaps as small as 5mm wide. Check thoroughly around doors, windows, vents and pipes. Seal possible entry points with wire wool embedded in quick-setting cement. 
• Seal food in glass containers Focus on easy-access foods like flour, sugar and cereal. And read our food storage tips.
• Keep bins and bin bags secure Empty your bins frequently and make sure bin lids are closed. Find the sturdiest options in our guide to the best kitchen bins and best bin bags.
• Don't leave pet food out overnight Pet food can attract mice and other rodents. Clean your pet's bowls every day and don't refill them until breakfast.
• Declutter regularly Keeping a tidy home can reduce the number of hiding places rodents have. See our tips for decluttering your home in three easy steps.

For more information on what to do if you spot a rodent, see our guides to getting rid of mice in your garden and how to deter rats from your garden.

2. Bedbugs

Bedbugs are typically dormant in lower temperatures, so you may think you won't have to deal with them in winter.

But Which? Trusted Trader Pests R Us Ltd, based in London, warns that as the heating is turned up and beds are warmed with electric blankets and hot water bottles, the increase in temperature can make bedbugs active again.

'Bed bugs are attracted to body heat, carbon dioxide and human scent,' said managing director Indu Kowarthanan. 'So if you're using the bed, especially with electric blankets or hot water bottles, the warmth can signal that a host is present and prompt them to come out of hiding and feed.'

Typical signs of bedbugs (aside from simply seeing them) include new red, itchy bites on your skin, and small brown spots (faecal deposits) on bedding or furniture. If you've got new bites but don't know what has caused them, see our guide to insect bites and stings.

While everyday warmth from heated bedding can encourage bed bugs to come out of hiding, this is very different from deliberate high-heat treatments, which are designed to kill them.

Exposing the pests to temperatures greater than 45°C for at least 30 minutes has been shown to be effective, so you could try washing clothes in a hot cycle in the washing machine, tumble-drying your clothes or treating the area with a steam cleaner. For more tips on tackling bedbugs, head to our dedicated advice: how to get rid of bedbugs.

How to prevent bedbugs this winter

• Wash your clothing and bedding regularly We cover how frequently you should wash your pillow cases, sheets, mattress protectors and more in our guide: how often should you wash your bedding?
• Inspect crevices where bedbugs could be hiding Play close attention to areas where infestations could go unnoticed, and vacuum regularly. A handheld vacuum cleaner can make this task easier.
• Get a mattress protector These can help reduce potential hiding places for bedbugs. See the best mattress protectors to find the right one for you.

Got a trip planned? Find out how to check your hotel room for bedbugs

3. Grey squirrels

While many people enjoy seeing grey squirrels in their gardens, they can cause problems if they get too close to homes or feeding areas.

Grey squirrels don't hibernate and may try to find their way into warmer places over the winter months, such as your attic, roof or garage.

As well as being noisy, they can potentially cause damage to your home by chewing through cables, timber, insulation and pipes. Grey squirrels can also do serious damage to trees by gnawing off the bark, and they can deter birds from feeding by raiding bird feeders. It's worth investing in a squirrel-proof bird feeder if your feathered friends are being disrupted.

How to deter grey squirrels this winter

• Protect your outdoor plants Use a 25mm square or hexagonal mesh to surround your bulbs (a favourite food of squirrels) and other plants. If you have a greenhouse or somewhere sheltered to keep your more vulnerable plants, it can be a good idea to move them in there temporarily.
• Block holes where they could be gaining access Much like mice and rats, squirrels can gain access to your house through holes and gaps. Check spaces like your attic and garage for any holes and seal them.
• Remove any tree branches offering access into your home Tree work is a tough and dangerous job, so it's probably worth getting a professional to do it. Use our guide to getting help in the garden to find the right trader for you.

For more on deterring grey squirrels, see our guide how to keep squirrels out of your garden

4. Woodlice

Woodlice prefer cool, damp conditions, so they’re most commonly found indoors in autumn and winter, often appearing in bathrooms, kitchens and under sinks.

They don't wreak havoc on your home the same way many other pests but their presence can indicate excess moisture, which may lead to damp problems such as mould.

Additionally, woodlice may be found in or around houseplants if the soil is damp, as they feed on decaying organic matter. They don't cause any damage and can be collected up and put outside.

How to prevent woodlice this winter

• Control the temperature and humidity within your home Woodlice thrive in cold, damp environments. Keep your house warm and dry and stop condensation before it causes damp – use one of the best window vacuums or best dehumidifiers. You might also want to use draught excluders around your doors or windows. 
• Reduce damp areas outside your home Removing plant debris from pots and areas close to your house can reduce damp habitats where woodlice gather, making it less likely they’ll move indoors during colder months. This will also help if you're dealing with slugs and snails.

If woodlice are becoming a nuisance, see our guide on how to get rid of woodlice

5. Woodworm

Woodworm is the larvae of a wood-boring beetle.

Typically in spring and early summer, adult female beetles lay eggs in cracks, crevices and pores in untreated or damp wood.

The eggs usually hatch after a couple of weeks, and the larvae then tunnel through the wood, feeding as they grow. Once the worm is close to the surface, it pupates into an adult beetle, emerges, mates, and the cycle begins again.

Woodworm activity slows in cold weather, though it can still develop in warmer, damp wood, such as that within a building. Damp conditions can also make wood more vulnerable to infestation, so if you’re concerned, see our guides: how to get rid of damp and what kind of damp is affecting my home? 

Winter can be a good time to inspect timber, address damp problems and plan treatment, helping to prevent further damage and giving you peace of mind for the year ahead. 

Woodworm treatment products are available from some hardware stores and online. Or head to Which? Trusted Traders to find a reliable pest control service.

How to prevent woodworm this winter 

• Look for holes in timber Small, round holes in timber – such as loft beams or floorboards – can be a sign of woodworm. Spotting these early can help you assess whether further investigation or treatment is needed. 
• Treat wooden beams, furniture or other wooden structures Woodworm is more likely to affect untreated or damp wood. Sealing timber with paint, varnish or a suitable wood treatment can help prevent beetles laying eggs and reduce the risk of future infestations.
• Optimise ventilation and control the humidity within your home Keeping timber dry is key to keeping woodworm away. Stop condensation before it causes damp and rot with one of the best dehumidifiers.

See more expert tips on how to treat woodworm

When to call professional pest control

Some minor pest problems can be solved with DIY methods, but if the infestation turns into something unmanageable or you don't feel comfortable tackling it yourself, it may be time to call in the professionals.

You can find Which?-endorsed pest control services through Which? Trusted Traders or use our handy tool below.

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