There are a number of key signs to be on the lookout for that could indicate you have mice in or around your home. You may start to encounter their waste. House mouse droppings may either be soft and moist or dried and solid. Droppings measure about 0.125-0.25 inches long and are typically rod-shaped with pointed ends. House mouse urine also has a distinct ammonia-like smell that can be a clear indication that your home has unwanted invaders.
As house mice travel around your home, evidence of their movement is often easily spotted. Rodents typically use the same pathways when moving about, resulting in easily visible trails of rub marks, droppings and footprints. A house mouse’s front feet leave four-toed prints and their hind feet leave five-toed prints, while their bodies leave oily rub marks on the walls along which they travel.
House mice can also leave gnaw marks around homes, which can be either rough or smooth. They also form burrows using material like insulation and may eat seeds, cereals, or insects they encounter in your home. Of course, if you ever see an actual mouse within your home, it is likely just one of many hiding just out of sight.