Best practices for nuisance wildlife control operators in New York State

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Ch 5: Step one: Asses the situation

 Signs of wildlife presence

Use your knowledge of animal behavior | Interview | Inspection | Signs of wildlife

Wild animals usually provide numerous signs of their presence. Once you've gained experience in "reading" these signs, the clues you gain from your site inspection and customer interview should help you identify the species, estimate the number of animals present, and find the areas where they're most active.

• Visual sighting. This is one of the easiest ways to identify the species (if you can trust the observer). You may also find carcasses. If nocturnal animals are often seen during the day, this may mean that the animal has young and is feeding more often, or that the local population is high, especially with rats and mice. If dealing with a bat colony, you may quickly identify the species but have a harder time locating the entry holes. You can use this to your advantage. Stand outdoors at dusk or dawn, and watch where the bats enter or leave the building. There's the hole!
   
• Sounds. Various squeaks, growls, cries, hisses, chitters, screeches; gnawing; or clawing, scampering, and climbing inside the walls, above the ceiling, between the floors, or underneath cabinets. Learn to tell the sounds of adults from those of young.
   
• Odors. You may smell the droppings, fermenting urine, or body oils of wildlife that are living indoors. With a little experience, you can tell the odor of a house mouse from that of a rat. Skunks have a well-known scent, but woodchucks can also be told by their odor. Dens of other animals, including raccoons, have their own perfume.
   
• Droppings may be found along runways, near shelters, in piles near an entry hole, or in other places used often. Fresh droppings are shiny and soft in texture, while old ones are dry, lighter in color, and hard. Old droppings crumble easily.
   
  

  Left: You'll often see a pile of bat droppings under the main entry hole. Right: Notice the urine stains on the chimney (from bats).

   
• Urine. You can see rodent urine using an ultraviolet light—it glows blue-white. Unfortunately, other materials also do this, which can be confusing until you become familiar with the typical background fluorescence of a home or office. You may also notice discoloration on building materials, often in attics or crawl spaces. That's caused by a large amount of urine, which could indicate the presence of raccoons, flying squirrels, or a large bat colony.
   
• Nests and food caches can sometimes be found when cleaning garages, attics, basements, closets, and other storage places. Rats, squirrels, and other rodents often store food in attics.
   

• Animals often gain entry under the eaves, as did a squirrel in this home.

  Entry sites (holes, cracks, loose siding). The location, size, and condition of the entry sites are important clues to the species involved.
   
• Burrows. Woodchucks, chipmunks, moles, voles, and Norway rats burrow, and you can learn to tell their burrows apart. (Other animals, including raccoons and skunks, will use burrows but they don't make them). The location of the burrow, its size, the type and number of entrances, and objects located near the burrow will help you identify the species.
   
• "Leftovers." You'll sometimes find the remains of a meal near an animal's den. You may be able to identify what the animal was eating, and that can help you identify the animal using the den. For example, you'll often find a fair amount of prey remains, such as rabbit fur, near the den of a fox or coyote. If there's no sign of prey, then you're probably dealing with a herbivore, such as a woodchuck.
   
• Runs. Smooth or worn trails may be found next to walls, along fences, or under bushes and buildings. Runs within buildings may be well-polished trails that are free of dust. Trails through insulation are common.
   
• Smudge marks are often seen in the animal's run where it rubs against a surface during its travels, leaving behind dirt and oil from their fur. Look on pipes, beams, against walls, and on the outside edges of holes.
   

• Left: A raccoon climbed this pipe to gain entry to the attic. See the marks? Right: Buildings are vulnerable at their joints. Check carefully for smudges that show an animal's been going in and out.

  Tracks and claw marks. Footprints, tail marks, and wing prints may be found in dusty surfaces, sand, soft soil, and in snow. If the surface doesn't show tracks well, you can sprinkle nontoxic tracking dust (such as chalk powder, flour, or unscented talc) in a likely area, then return later to see if there are any tracks. When used outdoors, the dust must be protected from wind and rain. You may find claw marks on woodwork, trees, or in dust. Consider photographing and labeling the images (after you're sure you've properly identified the species).
   
• Hair, feathers, or shed skins. You may find tufts of hair on a fence or baseboard, feathers in an attic or above a dropped ceiling, or, less often, the shed skin of a snake. With practice, you may be able to identify the species from this sign. To improve your identification skills, consider making some hair sample charts. Clip a tuft of hair from a nuisance animal you've dispatched, and attach it to the chart with the species identified.
   

• What happened here? A squirrel, trapped in a basement, tried to chew its way out. Top: the squirrel tried to squeeze underneath the door that led to the basement, gnawing and scratching at the bottom of the door and the rug. See the bits of wood and shredded fabric? Bottom: It also chewed on the window in the basement, hoping to escape that way. The squirrel chewed most of the mullions down to bare wood. See the bits of wood on the ledge?

  Gnawing (wood chips, tooth marks, holes, shredded fabrics, frayed wires). Look for evidence of chewing wherever wildlife might try to enlarge a crack or enter something. Wood chips may be seen near baseboards, doors, basement windows, kitchen cabinets, furniture, and stored materials. You could find shredded clothing, or see toothmarks on pipes. Rodents and raccoons often chew on the insulation around wires. The size of the toothmarks (or of a hole chewed in a baseboard) will frequently help you tell whether you're dealing with rats, squirrels, or mice.
   
• Pets become excited. When cats or dogs hear or smell rodents in some inaccessible spaces such as a wall, they may become enormously interested, whining, sniffing, and scratching at the spot.
   
• Access routes. Walk around outside and try to imagine the route the animal might have used to gain entrance to the building. Are there trees or utility lines near the roof? Could it have crawled under a porch, up a chimney, or along a downspout? Is there an attached garage that might have been left open? These clues point to likely culprits. Skunks, for example, aren't going to jump from a tree branch onto the roof, and squirrels aren't as likely to wriggle in underneath a porch.

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