Winter: mice, moths and the home you leave empty

A home left empty over winter is quiet, sheltered and, if anything edible was left behind, generous. That is all a mouse wants. Clothes moths like it too: wool nobody moves for months is ideal for them. Whether it is a second home, a long holiday or a rental between tenants, the worry is the same. What will I find when I open the door?

Usually much less than you fear, if you spend an afternoon on it before you go. Pests move into empty homes for food and shelter. Take the food away, close the obvious ways in, and leave something that tells you what happened while you were gone.

Winter looks different around the world. In cold places, mice are the main concern. In warm ones, cockroaches and ants keep going all year, and the same checklist covers them.

Why empty homes attract them

• Nobody disturbs them. No footsteps, no lights, no one opening the cupboard under the sink.
• Food gets forgotten. An open bag of rice, a packet of biscuits, the bird seed in the shed.
• Drains open up. Over a long absence, the water in pipe traps can dry out, which leaves a path up from the drains.
• Problems grow unseen. A small issue in November has had months to build by the time anyone notices.

Before you leave: one afternoon

1. Clear the food. Open packets, flour, cereal, spices, pet food and bird seed. Take it, give it away or bin it. What stays goes in tins or hard, sealed containers. Cardboard and plastic bags are not enough for months.
2. Deal with the fridge. Leave it running with only sealed things inside, or empty it, clean it, switch it off and prop the door open so it does not grow mould.
3. Empty and wash the bins, inside and out.
4. Clean the crumb spots. Under the toaster, behind the cooker, the cutlery drawer, down the sofa.
5. Plug the drains and close toilet lids. Sinks, bath and shower. Fix any drips. Ask your plumber, building manager or insurer what to do about the water and heating while you are away, because that depends on the building and the climate.
6. Close the gaps. A brush strip under outside doors, steel wool and sealant round pipes under the sink, mesh over vents. Our page on sealing gaps shows how.
7. Put wool away clean and sealed. More on that below.
8. Leave monitor traps, dated. Kitchen, bathroom, by the front door. When you get back, they tell you what came in and roughly where. See how to use monitor traps.
9. Ask someone to look in if you can. A neighbour or friend who runs the taps, checks for leaks and glances at the traps now and then.

The full version, with what to do if you already have cockroaches, is in going away for months: how to stop pests moving in.

Mice: seal, do not set

If you have seen signs of mice this autumn, the most useful thing you can do before leaving is close the way in. Look under the sink, behind the cooker and fridge, where pipes go through walls and around the boiler. Fresh droppings along a wall point to the route.

Do not leave live catch traps set unless someone can check them every day. A mouse left in a trap for days suffers and dies, which is the opposite of humane. Leave them unset and set them when you are back. No poison and no glue boards either: they cause suffering, and a poisoned mouse can die somewhere you cannot reach. Mice keep coming back has the full humane plan, and glue and bucket traps explains why we leave those out.

Moths: the slow surprise

Clothes moths are the pest people most often find months later, as holes in a jumper or a rug. It is the larvae that do the damage, and they go for wool, cashmere, silk and felt, especially anything with sweat or food marks on it.

• Wash or clean wool before storing it, as its care label allows.
• Store it sealed: zip bags, plastic boxes with lids, or garment bags closed at both ends.
• Vacuum under beds and along carpet edges before you go, where larvae like to feed undisturbed.
• Hang a clothes moth pheromone trap in the wardrobe room, dated. It catches males only, so it will not end a problem, but it tells you on your return whether moths were flying.

How to stop moths eating wool and cashmere covers storage, and do moth pheromone traps get rid of moths? covers what the trap can and cannot tell you. Mothballs are not needed: see clothes moths without mothballs.

Pantry moths are the kitchen version. Any dry food left in a cupboard can host them, and a whole winter is plenty of time. Clearing the food is the fix. If you come back to webbing in a packet, what food do I have to throw out? walks through it.

Holiday lets and empty rentals

If you let the place between your own stays, or it sits empty between tenants, the same steps apply, plus a check before each new arrival. Our pages for second homes and rental hosts have more. Clearing a rental between tenants and stopping bed bugs between guests cover the turnover. And if guests may meet a mouse in a rural place, telling guests about mice or bugs helps you say it honestly.

If you are the tenant and you come back to signs of pests, tell your landlord or agent in writing, with dated photos. How to document pests for your landlord covers what to send. Who is responsible varies by country: in the UK, council environmental health can advise, and elsewhere the local housing authority or a tenants’ union.

When you get back

1. Read the traps before you unpack. Empty is good. A catch or two: note what and where.
2. Look for droppings and gnaw marks under the sink, in cupboards, along skirting boards and in the loft if you can reach it. Our page on droppings and egg cases helps you tell mouse from insect.
3. Check the wardrobe and the food cupboard. Holes, silky webbing, little cases on fabric, clumped flour.
4. Run every tap and flush the toilets to refill the drain traps.
5. Put fresh traps down for a couple of weeks once you are settled.

Cleaning up mouse droppings: wear gloves, spray the droppings with disinfectant and let it soak, then wipe up with paper towels. Do not sweep or vacuum them dry, as that lifts dust. If anyone checking the house brings children or a dog, tell them where traps and any bait are, and keep them out of reach as the label says.

What you find, and what it means

• Mouse droppings: something got in. Find the route, seal it, and catch any that are still inside with live traps checked every morning.
• One cockroach on a trap: worth checking, not worth panicking over. I saw one cockroach explains how to find out in a week or two.
• Young cockroaches on a trap: they are breeding inside. Start this week: baby cockroaches, what now?
• Moths in the pheromone trap: look for the source before you treat. Rugs, carpet edges and stored wool come first.

And if it is something bigger in the roof, like squirrels, animals in the roof covers humane removal. Many wild animals are protected by law, so check before you seal anyone in or out.