Signs of a Mouse Infestation

Mice are quiet, fast, and often active when you’re asleep, which makes spotting them difficult.

But while you may not see them, they leave behind clear evidence of their presence.

Knowing the signs can help you act before the problem gets out of hand.

1. Droppings

One of the most obvious signs is the presence of small, dark droppings.

Mouse droppings are typically 3–6 mm long, resembling dark grains of rice, and are often found near food sources or along walls.

Mice gnaw constantly to keep their teeth from overgrowing.

You may spot small chew marks on skirting boards, furniture, food packaging, or even wiring.

At night, mice become more active, often creating scratching or scurrying sounds inside walls, ceilings, or under floorboards.

Mice build nests from shredded paper, fabric, or insulation.

Look in hidden areas like behind appliances, inside cupboards, or in loft spaces.

Mice leave greasy rub marks along walls and baseboards as they follow the same routes.

These stains are caused by the oils in their fur.

Cats or dogs may become fixated on certain areas of the home, sniffing or pawing at walls or cupboards if they sense rodents inside.

A strong, musky odour can build up in areas where mice are active, especially if the infestation is large.