Often, mice haven’t just turned up —they’re already there, hiding in walls, lofts, and cupboards. The trouble is, they’re quick, and mostly nocturnal. You might not know they are there, and by the time you see one, you could be dealing with a full infestation.
Knowing the signs is important. Spot them soon enough, and you can act fast.
The First Warning Sign: Droppings
One of the clearest indicators of a mouse problem is the presence of droppings. These are small, dark, and shaped like grains of rice—usually around 3 to 6 mm long.
You’ll often find them near food sources, under sinks, behind the fridge, or inside kitchen cupboards. If the droppings are moist and shiny, they’re fresh. That means mice are actively using the area.
Even if you only see a few, it’s worth investigating further. Mice can produce up to 80 droppings per night, so even a small amount suggests more could be hidden nearby.
Noises in the Night
Mice are most active when the house is quiet—especially at night. If you hear scratching, scuttling, or squeaking sounds in the walls or above the ceiling, it’s a strong sign of rodent activity.
Lofts, basements, wall cavities, and under-floor areas are all popular hiding places. Many people ignore these sounds at first, thinking it’s just the house settling. But if the noise is regular, especially after dark, you may be facing an early-stage infestation.
Grease Marks and Smudges
Mice use the same routes over and over again. As they squeeze through narrow gaps and along skirting boards, they leave behind greasy smudge marks.
These marks are caused by the oils in their fur. Over time, they build up, particularly near entry points and around kitchen cabinets. If you’re not sure whether a mark is from mice, try wiping it. If it’s stubborn and reappears after a day or two, that’s your confirmation.
Some pest control professionals also use UV light to identify urine trails, which mice leave behind as they travel. It’s unpleasant, but it reveals how widespread the mouse problem may be.
Shredded Materials and Hidden Nests
Mice like quiet, dark, and undisturbed areas to build their nests. They’ll shred anything they can find—paper, insulation, cloth, even plastic packaging—to create a warm, soft hiding place.
If you find small piles of these materials tucked behind appliances, in airing cupboards, or beneath floorboards, take note. These nests are typically close to food and water sources, meaning the mice are living—not just passing through.
A single nest often supports multiple mice, so even a small discovery should be taken seriously.
Unusual Smells or Allergic Reactions
Mice leave behind more than just droppings. Their urine and scent trails can create a strong, musty smell—especially in confined spaces like under stairs or behind kickboards.
This odour is often compared to ammonia. If you notice it getting stronger, there’s likely a large group nearby.
Mice can also trigger allergies. Dander, hair, and particles from droppings become airborne and may worsen symptoms for people with asthma or sensitivities. If someone in the household is sneezing more than usual, and there’s no obvious cause, it might be time to investigate.
Seeing a Mouse in Daylight
This is rarely a sign of just one rogue mouse. More often, it’s evidence of a growing infestation.
Most mice avoid open areas and stay hidden during the day. If you see one in daylight, it usually means the nest is overcrowded, and they’re being forced to explore new territory.
Act quickly. Unless you have a pet cat that has brought a mouse inside, a visible mouse in your living space probably means the population is nearby and spreading.
Your Pets Know Something’s Up
Cats and dogs can sense pests long before you do. If your pet suddenly becomes obsessed with a certain cupboard, corner, or appliance, don’t dismiss it.
Scratching, barking, or sniffing intensely at hidden spaces could mean there’s movement inside. Trust their instincts—animals often see and hear what humans overlook. It might just save you time and money in pest control later.
Don’t Wait for Damage to Act
One of the biggest mistakes people make is ignoring the signs until they have no choice. Mice breed quickly. A single pair can produce dozens of offspring in a matter of weeks. That’s why early intervention is so critical.
Professional pest control mice services use targeted treatments, identify nesting sites, and block entry points to prevent re-infestation. DIY methods can help in the short term, but they’re rarely enough once a nest has been established.
Final Thoughts
Mice like to stay hidden, but they leave behind clues. Droppings, noises, smells, and pet behaviour can all point to an infestation long before the real damage begins.
So if you’re worried you might have a mouse problem, don’t wait. The earlier you act, the easier it is to put things right.
And if you’re in doubt, call a local pest control expert to inspect and give you advice.