Signs of Rats
Rats are active all year, mostly at
night. However, when disturbed (weather change, construction, etc.), hungry, or
when living in crowded conditions they are seen at any hour.
It is not easy to tell how many rats are using an area. However, you can use their signs as a rough guide to whether the population is low, medium, or high. Use a powerful flashlight to search for their sign in dark places and to spot the animals after dark.
Where rat numbers are low, no sign other than a burrow entrance 2 to 4 inches in diameter may be seen.
In a medium-populated area, droppings and gnawing’s can be found, and rats will be heard in or under a structure at night. In addition, cats and dogs may excitedly probe an area of floor, wall, or other area where rats are present, especially if rats have only recently entered.
When a high rat population is present, fresh droppings and signs of gnawing will be common. Also, rats may be seen and heard both day and night.
Rat Burrows
Norway rat burrows are found singly or in groups along building foundation walls, under slabs, in overgrown weedy areas, beneath debris and buildings, and in moist areas in and around gardens and fields. Active burrow entries are 2 to 4 inches in diameter, free of dirt, leaves and spider webs, and are surrounded with smooth, hard-packed soil. A fresh entry will have soil pushed out in a fan-shaped pattern.
To determine if an existing burrow is occupied, fill the entry with some wadded-up newspaper, leaves, or dry soil. If rats are using the burrow, they will reopen and clear the hole in a couple of days during good weather.
Rat Trails
Rats tend to travel the same route—along walls, along fences, under bushes—nightly. Trails appear as narrow (wide enough for only one rat), worn paths. Roof rats can often be seen at night running along overhead utility lines or fence tops.
Rat Tracks
Rat tracks appear in dust or soft, moist soil. A rat's footprint is about 1/2 inch long and shows four or five toes. Rats may also leave a tail dragline in the middle of their tracks.
Rat (and mouse) tracking patches can be placed in suspected rat areas to reveal footprints. A tracking patch is a light dusting of an inert material such as clay, talc (unscented baby powder), or powdered limestone. Don't use flour, which can attract rats and other animals. A suitable patch size is 12 x 4 inches. When inspecting tracking patches, shine a flashlight at a low angle, causing the tracks to cast distinct shadows.
Rat Droppings
A single rat can produce 50 droppings daily. Most droppings are found where rats rest or feed. Fresh droppings are black or nearly black, look wet, and have the consistency of putty. After a few days, droppings become dry, hard, and have a dull appearance. After a few weeks, droppings become gray and crumble easily.
Note that old droppings moistened by rain look like new droppings; however, if crushed, they will crumble.
Rat Gnawing
A rat's incisor teeth grow at the amazing rate of 5 inches per year. Rats keep their extremely hard teeth worn down by continuously working them against each other and by gnawing on hard surfaces. Look for signs of gnawing on floor or ceiling joists, door corners, siding, and around pipes in floors and walls.
Rat Rub marks
Body oil and dirt rub off of rat fur and can become noticeable along frequently used trails. Look along wall/floor junctions, where rats move around obstacles, and at regularly used openings in walls, floors, and ceilings.
Rat Sounds and Smells
Rats make squeaks and fighting noises, as well as clawing, scrambling, and gnawing sounds in the walls and other parts of buildings. These sounds may be so loud it seems a larger animal is present. Areas occupied by rats often have a musky smell. One dead rat can cause considerable odor.
It is not easy to tell how many rats are using an area. However, you can use their signs as a rough guide to whether the population is low, medium, or high. Use a powerful flashlight to search for their sign in dark places and to spot the animals after dark.
Where rat numbers are low, no sign other than a burrow entrance 2 to 4 inches in diameter may be seen.
In a medium-populated area, droppings and gnawing’s can be found, and rats will be heard in or under a structure at night. In addition, cats and dogs may excitedly probe an area of floor, wall, or other area where rats are present, especially if rats have only recently entered.
When a high rat population is present, fresh droppings and signs of gnawing will be common. Also, rats may be seen and heard both day and night.
Rat Burrows
Norway rat burrows are found singly or in groups along building foundation walls, under slabs, in overgrown weedy areas, beneath debris and buildings, and in moist areas in and around gardens and fields. Active burrow entries are 2 to 4 inches in diameter, free of dirt, leaves and spider webs, and are surrounded with smooth, hard-packed soil. A fresh entry will have soil pushed out in a fan-shaped pattern.
To determine if an existing burrow is occupied, fill the entry with some wadded-up newspaper, leaves, or dry soil. If rats are using the burrow, they will reopen and clear the hole in a couple of days during good weather.
Rat Trails
Rats tend to travel the same route—along walls, along fences, under bushes—nightly. Trails appear as narrow (wide enough for only one rat), worn paths. Roof rats can often be seen at night running along overhead utility lines or fence tops.
Rat Tracks
Rat tracks appear in dust or soft, moist soil. A rat's footprint is about 1/2 inch long and shows four or five toes. Rats may also leave a tail dragline in the middle of their tracks.
Rat (and mouse) tracking patches can be placed in suspected rat areas to reveal footprints. A tracking patch is a light dusting of an inert material such as clay, talc (unscented baby powder), or powdered limestone. Don't use flour, which can attract rats and other animals. A suitable patch size is 12 x 4 inches. When inspecting tracking patches, shine a flashlight at a low angle, causing the tracks to cast distinct shadows.
Rat Droppings
A single rat can produce 50 droppings daily. Most droppings are found where rats rest or feed. Fresh droppings are black or nearly black, look wet, and have the consistency of putty. After a few days, droppings become dry, hard, and have a dull appearance. After a few weeks, droppings become gray and crumble easily.
Note that old droppings moistened by rain look like new droppings; however, if crushed, they will crumble.
Rat Gnawing
A rat's incisor teeth grow at the amazing rate of 5 inches per year. Rats keep their extremely hard teeth worn down by continuously working them against each other and by gnawing on hard surfaces. Look for signs of gnawing on floor or ceiling joists, door corners, siding, and around pipes in floors and walls.
Rat Rub marks
Body oil and dirt rub off of rat fur and can become noticeable along frequently used trails. Look along wall/floor junctions, where rats move around obstacles, and at regularly used openings in walls, floors, and ceilings.
Rat Sounds and Smells
Rats make squeaks and fighting noises, as well as clawing, scrambling, and gnawing sounds in the walls and other parts of buildings. These sounds may be so loud it seems a larger animal is present. Areas occupied by rats often have a musky smell. One dead rat can cause considerable odor.
This information was provide by the Washington State Department of Fish and Wildlife, Russell Link, and Michael Holmquist
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