Signs of mice in the house - and the first-weekend response

Autumn sends mice house-hunting, and they need a hole the width of a biro to move in. Confirming the infestation early and responding in the right order is the difference between a weekend errand and a winter flatmate.

The signs, most reliable first

Droppings - small, dark, rice-grain pellets along walls, behind appliances, in cupboards. Fresh ones are soft and dark. Gnaw marks - on food packaging, skirting boards, cables (gnawed wiring is a genuine fire risk: which makes this a safety issue, not just a nuisance). Sounds - scratching or scurrying at night, from ceilings, walls or under floors. Smears - dark grease marks along regular run routes. Nesting material - shredded paper or fabric in quiet corners. One sign is suspicion; a cluster is confirmation.

The response, in the right order

1. Seal first, trap second. New mice replace trapped mice indefinitely if the door stays open. Sweep the exterior wall line: gaps around pipes, vents and door bottoms get packed with steel wool and sealed over - mice cannot chew through steel wool easily, and it holds caulk in place.

2. Starve them. Food in glass or metal containers, floors crumbed, pet food not left out overnight, bins with lids. A sealed house with no calories is a bad tenancy.

3. Trap along the run routes. Snap traps perpendicular to walls, trigger side against the skirting, where you found droppings - baited with peanut butter, checked daily. This is standard homeowner territory; humane live traps work too, but release must be far away or the mouse commutes home.

Where the professional line sits

Droppings in multiple rooms, signs that persist after two honest weeks of sealing and trapping, noises you cannot localise, or anything involving a business or rental property: bring in pest control. That is not defeat - populations behind walls do not respond to enthusiasm - the honest DIY-or-pro sorting is here.

Prevention next autumn is the same list done in September: walk the exterior, seal the gaps, mind the food - the ants guide covers the kitchen half of the same discipline, and one sighting handled calmly is the rule for everything that crawls.