Besides seeing an actual mouse, there are quite a few ways to determine if you have a mouse problem. Even one mouse will leave dozens of droppings per day, meaning a major infestation might be leaving hundreds or thousands of droppings. Look for these tell-tale signs in cupboards, gardens, and under furniture. Another sign of an infestation is small, sometimes perfectly round holes in cereal boxes, cabinets, and other chewable barriers that separate mice from food. Mice might also chew through computer and other electronic wires and nibble on leaves and vegetables in a garden.
Mouse droppings look like dark grains of rice or beans, and they’ll almost magically appear in all sorts of places. Mice leave these droppings frequently throughout the night, and even a dozen mice should be noticeable if you are looking in the right places. Pay special attention to areas near food and areas that are warm and dark. Droppings are a sure sign of a mouse problem, but they should not be confused with cockroach eggs, which resemble a dark but translucent capsule. Mouse droppings are solid, darker in color, and normally not uniform in shape.
If you failed to find mouse droppings, look for holes in cupboards, walls, and all other places a mouse might want to pass through. Sometimes a mouse hole is a neat circular hole that looks as if someone drilled a hole for a pipe but did not place it. Other times it is a crude creation by a mouse that only chewed enough to get through. A mouse hole is sometimes slick with grease from mice fur, which can be greasy, similar to an unwashed human’s hair. If you have outdoor sheds or other buildings, check them too.
Besides chewing through obstacles, mice tend to chew on cords and other mundane items. In fact, it is not uncommon for mice to make a home in a vehicle and chew through important wiring. When not disabling a vehicle or computer, mice might be in the garden nibbling on leaf edges or vegetables. If so, the leaves are probably frayed in an odd way, or there is a distinct path through the garden. Mice tend to take the same path toward a destination, repeatedly trampling on the grass and making their route obvious.
Lastly, one way to discover a mouse problem is to find a mouse. Setting traps, cameras, or just being quiet at night and then turning on a light can reveal a mouse. If there is one mouse, there are probably more, and it is safe to say you have a mouse problem.