Mouse, Roof Rat or Norway Rat? Telling Them Apart in Stuart.

Droppings are the first thing most people can examine safely from a distance. House mouse droppings are small, about the size of a grain of rice, pointed at the ends and scattered widely. You may find dozens in a single drawer or along a baseboard.

Roof rat droppings are larger, around half an inch, with pointed or spindle-shaped ends. They tend to appear in attics, along rafters, on top of walls and beneath trees where the animals feed. Norway rat droppings are the largest, closer to three quarters of an inch, with blunt, capsule-shaped ends. They collect near burrows, along ground-level runs and in garages and sheds.

Fresh droppings are dark and slightly shiny. Older ones dry out, turn gray and crumble. If you see fresh droppings, activity is current. Do not sweep or vacuum dry droppings. Photograph them with something for scale, like a coin, and send the photo or describe it on the call.

Sound helps with location. Light, quick scratching in a wall or ceiling, especially in short bursts, often points to mice. Heavier thumping, rolling or scampering overhead at dusk or just after dark often points to roof rats in the attic. Rats can sound like a small animal running across a ceiling, and homeowners often compare it to a squirrel at night.

Noises low in the house, under floors, along the slab or from a shed, point to Norway rats. These animals prefer ground level and tend to dig. A gnawing sound from inside a wall, like a dull, repeated scraping, can come from any of them.

The time matters too. All three are mostly nocturnal. If you hear movement in broad daylight, a large population may be crowding the nest, or something else may be happening. Noting the time you hear it is useful information.

Roof rats are climbers and they use the aerial route. A rat running along a fence top, a power line or a palm trunk at dusk is almost certainly a roof rat. They nest in palm crowns, dense vines and attics. In Stuart that pattern is common because palms and mature landscaping are common.

Norway rats stay low. You may see one along a wall at night, near a dumpster or beside a burrow. Their burrows are two to three inches across, with smooth soil at the edge, beside slabs, under sheds and beneath groundcover.

House mice are small enough to hide almost anywhere. They live in walls, cabinets, stored boxes and appliances. You rarely see one, but you often see its signs in the kitchen, pantry and garage.

Gnaw marks vary by size. Mouse gnawing leaves tiny scratches and ragged holes about the size of a dime. Rat gnawing is coarser and leaves larger holes, with bite marks that you can feel with a fingertip. Fresh gnawing is pale and rough, while old gnawing is dark.

Rub marks are smears of grease and dirt along surfaces where an animal runs daily. Roof rats leave them on rafters, pipes and fence tops. Norway rats leave them low on walls and along the foundation. Mice leave faint marks along baseboards.

Nests help too. A mouse nest is a small ball of shredded paper, fabric or insulation, roughly the size of a fist. A roof rat nest is larger and often found high, in an attic, a palm crown or a hedge. A Norway rat nest is usually underground or in a protected lower space, with shredded material packed into a burrow.

The traps, the placement and the sealing are different for each animal. Mice are curious and will investigate a new trap right away. Roof rats are wary and may ignore a new object for days, so we place traps unset and then arm them. Norway rats are cautious as well, but they follow a fixed ground-level path, so placement along that path is key.

Entry points differ. A mouse needs a gap the width of a pencil. A rat needs an opening about the size of a quarter. A roof rat may enter at the roofline, through gable vents, tile returns and soffits. A Norway rat is more likely to enter at the foundation, a garage door or a pipe near the ground. Our exclusion and sealing work targets the right place for each.

Landscaping is part of it. Roof rats need trimmed palms and branches kept off the roof. Norway rats need food and burrows managed at ground level. Mice need pantry and garage storage addressed. One generic plan does not cover all three, which is why guessing wrong costs time and money.

Speed matters for how long you can wait. A female house mouse can produce a litter roughly every three weeks, with several young each time. Rats are somewhat slower but still prolific, and a pair of roof rats can raise multiple litters in a year in warm weather. The result is that a minor sign in June can be a crowded nest by fall.

That is why we encourage calling early. A visit for a few droppings is shorter and cheaper than a visit for a full attic. If you are on the fence, a quick call costs nothing and tells you whether the signs you see are worth acting on.

• Photograph droppings, gnaw marks and any nest, with a coin for scale.
• Write down where and when you hear activity.
• Note whether the sounds are overhead, in a wall or near the floor.
• Look for burrows, rub marks and gnawed fruit outdoors.
• Keep pets and children away from the area.
• Leave droppings undisturbed until the visit.

If you are not sure what you have, that is fine. Call the line and describe what you saw. Our rodent inspection and estimates service starts with confirming the animal, and then the plan follows. For a deeper look at each animal, see our mouse control and rat control pages.

Public health guidance from the CDC recommends wetting droppings with disinfectant and wiping them up with gloves rather than sweeping. We follow that, and so should you if you clean before a visit. In most cases it is better to wait until after the inspection so the technician can read the signs first.