We explain how to identify animal damage in or around buildings from cats, dogs, groundhogs, gophers, mice, bats, etc. and how we distinguish among these types of damage on or in buildings.

When we know what animal is causing trouble outside or inside of our building then we are ready to take the right steps to repair the damage and to prevent more animal damage in the future.

Page top photo: why is the bottom end of this downspout chewed open? Was a small animal hiding inside the downspout and did our dog rip the downspout end open trying to snag a little snack?

How to Distinguish Dog Chewing or Biting Damage from Insect Damage to Wood

What caused this damage to the wood in this photo of my home? Insects?

I am trying to figure out what caused the damage in the attached photographs.

Location is Columbia County, NY. There is no visible sawdust or debris, and I have not seen any insects.

Any help would be appreciated. - Anonymous by private email 2018/10/17

Reply: bad dog! chewed wood trim

Having seen damage done by nervous or irritated dogs who attack building components, trim, even drywall indoors and, of course, furniture, my bet is that a dog is or was at your property.

Reasons that this is animal damage not insect damage.

• There is no sawdust or frass
• Some of the bites or gouges continue as a scrape across the wood surface
• The edge of the wood trim has been ripped away showing torn wood grains - this is not characteristic of insect attack.

Bad dog!

Let's take a closer look at the holes and gouges themselves as well as the location where they appear.

The gouges into the wood are shaped as if penetrated by a roughly V-shaped or spike-shaped (sharp) tooth rather than coming from tunneling or wood-destroying insects.

And the holes and bite marks occur at an outside corner of wood trim: a really easy place for a dog to bite. You won't find these marks in the dead center of a wide board or cabinet or door.

(You might find dog scratches in such a centered location.)

You will see other photos of typical insect damage of all sorts in this article series.

Dog chewed away at the corner of one of our cabinets - is this mold showing?

Our dog chewed away at the corner of one of our cabinets in kitchen. Underneath is black. Is this mold? - On 2018-08-02 by Mallory -

Reply by (mod) - That's adhesive mastic, not mold but don't feed it to your dog

Mallory

I'm not sure: that could be a black mastic adhesive. Take a close look for evidence of a history of leaks or water passage.

In your photo I can't see water marks so I suspect that the black stuff is not mold.

Let us know what you see in those other checkpoints, especially in the floor of the cabinet interior and of course inside the cabinet at higher points if there is plumbing visible.

Watch out: don't let your pet (nor anyone else in your family) eat any building materials: plaster, drywall, splintered lumber, and asphalt-based tile mastic can all be sickening or fatal to animals.

Also see MOLD APPEARANCE - STUFF THAT IS NOT MOLD

Examples of Scratch-Damage by Dogs

Below: dog toenail damage to a wood floor. The scratches suggest this was a rather large or heavy animal.

The photo below shows scratches at a door that was addressed by a smaller dog. You'll notice that the damage is quite close to floor level.

Below: dogs anxious to be let outside may also scratch away at door trim, as our client indicates in the photo below

Below: scratches on this basement entry door appear high off of the floor, indicating that the dog who left this calling card, a Minneapolis Minnesota mastiff, is a big girl.

And just to be fair to the dogs, owners who don't let their dog out do to its business when it needs perform it will ultimately face floor damage like that shown below. Those are pet pee stains on a wood floor.

With over five decades of building damage inspection that included pet or animal damage, I have to say that the worst pet pee stains are usually where the pet peed on a carpeted-over floor. Leaving a peed-0on carpet and carpet padding in place, even if you try to wash or clean the carpet itself, will usually result in deep stains into wood flooring that are almost impossible to remove.

They extend to deeply into the wood to be removed by surface sanding.

Details are at

• ANIMAL STAINS & MARKS in BUILDINGS
• ANIMAL or URINE ODOR REMOVAL

Squirrel Damage Indoors: trapped Squirrel Goes Mad

Just about any wild animal and some pets who find themselves trapped alone in an empty building will go to great lengths to try to find or make an escape route.

In the process, whether the trapped raccoon, squirrel, rat, or other creature finds a way out or not, before the escape is made, considerable damage may ensue in the form of bites, chews, rips, digs, and of course feces and urine.

During inspection of an empty home in Poughkeepsie, New York, on entering the kitchen my attention was first captured by the pile of rough wood scraps in a pile on the floor (photo above).

I think that a maintenance worker swept up the gnawing wood shreds but didn't bother to collect the pile to toss into the trash - as there was no trash can nearby.

On seeing wood fragments like those above one would be inclined to look around for their source - shown below.

You might imagine an animal trapped inside this home, drawn by the light and the outside view of the window, gnawing frantically to try to create an escape route to the outdoors.

Looking around we found the window muntins, sills, and a few other wood components badly damaged by gnawing.

Above and below: window frame damaged by a gnawing animal, probably a squirrel or raccoon trapped in this home.

Comparison photos: Insect Damage is not the same as Animal Damage

My photo just above shows, for contrast, carpenter ant frass or "sawdust" and damage at wood in a building.

Other examples of animal biting, chewing, or digging that causes damage at properties as well as animal allergens, urine removal, and odors are discussed in the animal damage links given just below.

Animal & Wildlife Damage Detection, Repair, Prevention Resources

• Booth, Thurman W. "Bird dispersal techniques." (1994).
• Clark, Kathleen E. "Attracting and managing for wildlife." In Handbook of Urban and Community Forestry in the Northeast, pp. 397-409. Springer, Boston, MA, 2000.
• Cleary, E. C., & Dolbeer, R. A. (2005). WILDLIFE HAZARD MANAGEMENT AT AIRPORTS: A MANUAL FOR AIRPORT PERSONNEL [PDF] USDA National Wildlife Research Center-Staff Publications, 133. original source: https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1127&context=icwdm_usdanwrc
• Conover, Michael R., William C. Pitt, Kimberly K. Kessler, Tami J. DuBow, and Wendy A. Sanborn. "Review of human injuries, illnesses, and economic losses caused by wildlife in the United States." Wildlife Society Bulletin (1973-2006) 23, no. 3 (1995): 407-414.
• Cooper, M.E., 2016. Law affecting British wildlife casualties. In BSAVA manual of wildlife casualties (pp. 7-16). BSAVA Library.
• Dreistadt, Steve H. Pests of landscape trees and shrubs: an integrated pest management guide. Vol. 3359. UCANR Publications, 2016.
• Flint, Mary Louise. Pests of the garden and small farm: A grower’s guide to using less pesticide. Vol. 3332. UCANR Publications, 2018.
• Gilsdorf, Jason M., Scott E. Hygnstrom, and Kurt C. VerCauteren. "Use of frightening devices in wildlife damage management." Integrated Pest Management Reviews 7, no. 1 (2002): 29-45.
  Abstract:
  Wildlife is often responsible for causing extensive damage to personal property, human health and safety concerns, and other nuisance problems because of their feeding, roosting, breeding, and loafing habits.
  
  Frightening devices are tools used in integrated wildlife damage management to reduce the impacts of animals, but the effectiveness of such devices is often variable. An animal's visual and auditory capabilities affect how the animal will respond to a stimulus. Frightening devices include pyrotechnics, gas exploders, effigies, lights, lasers, reflective objects, guard animals, bioacoustics, and ultrasonic devices.
  
  We examined scientific literature on the use of frightening devices to reduce bird and mammal depredation and compiled results to determine the effectiveness of such devices. When used in an integrated system, frightening devices may be more effective than when used alone.
  
  We conclude that the total elimination of damage may be impossible, but frightening devices and/or combinations of devices are useful in reducing wildlife damage. Ultrasonic frightening devices are ineffective in repelling birds and mammals whereas other devices offer some protection.
  
  The timely use of a variety of frightening devices can be part of a cost-effective integrated system to reduce wildlife damage to tolerable levels.
• Greene, Susan Darling. TRAP-SHY FERAL CATS IN PUBLIC SETTINGS [PDF] Probe (2001).
• Hyngstrom, Scott E., Gary E. Larson, and Robert M. Timm, eds. PREVENTION and CONTROL of WILDLIFE DAMAGE Vol. 1. [PDF] Lincoln, USA: University of Nebraska, 1994.
  
  Preface excerpt:
  
  This handbook is a comprehensive reference of North American vertebrate species that can cause economic damage to resources or become a nuisance at various times and places.
  
  It is intended for use by extension agents and specialists, wildlife biologists, animal control officers, public health personnel, pest control operators, teachers and students of wildlife biology, and others who deal with wildlife damage problems.
• Johnson, Ted, and Ruth A. Jacobs. Gallinaceous Guzzlers. Section 5.4. 1, US Army Corps of Engineers Wildlife Resources Management Manual. No. WES/TR/EL-86-8. ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS ENVIRONMENTAL LAB, 1986.
  
  Abstract : This report was prepared as a guide to assist Corps biologists and resource managers in developing and implementing artificial watering systems for wildlife where water supply is a limiting factor. The gallinaceous guzzler is a permanent self-filling watering device used to improve habitat conditions for wildlife in arid and semiarid regions.
  
  The technique is appropriate for habitat management programs for game birds such as California quail (Callipepla californica), Gambel's quail (C. gambelii), scaled quail (C. squamata), chukar (Alectoris chukar), ring-necked pheasant (Phasianus colchicus), and mourning dove (Zenaida macroura), as well as game mammels and certain nongame species.
  
  The guzzler is used extensively by the Washington State Department of Game and the US Army Engineer District, Walla Walla, and consists basically of a fiberglass cistern and a galvanized metal collecting apron.
  
  Details are given on the design, construction, installation, and maintenance of the guzzler, and specification drawings and lists of materials required are provided. Guidelines are presented on the application of guzzlers as part of a broader habitat management program in which food, cover, and water conditions are improved and properly interspersed.
• Messmer, Terry A., and Gerald W. Wiscomb. WOODPECKERS [DAMAGE MANAGEMENT] [PDF] Animal Damage Control, Utah State University, Wildlife Damage Management Series, w/ Utah Division of Wildlife Resources, USDA et als, (1998 - 2010) Retrieved 2019 09 27 original source https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=3302&context=wild_facpub
  This article is widely reproduced including by the North Dakota State University, the USDA-APHIS Animal Damage Control, and others.
  Excerpt:
  
  For the most part, woodpeckers are beneficial birds because of the large numbers of insect pests they eat. However, when wood-sided buildings, wooden fences, power poles, and orchards become the focus of their attention, serious damage can occur.
• National Association of State Public Health Veterinarians Compendium of Animal Rabies Prevention and Control Committee, Catherine M. Brown, Lisa Conti, Paul Ettestad, Mira J. Leslie, Faye E. Sorhage, and Ben Sun. "Compendium of animal rabies prevention and control, 2011." Journal of the American Veterinary Medical Association 239, no. 5 (2011): 609-617.
  
  Abstract excerpts:
  
  Rabies is a fatal viral zoonosis and a serious public health problem. All mammals are believed to be susceptible to the disease, and for purposes of this document, use of the term animal refers to mammals.
  
  The disease is an acute, progressive encephalitis caused by a lyssavirus. Rabies virus is the most important lyssavirus globally. In the United States, multiple rabies virus variants are maintained in wild mammalian reservoir populations, such as raccoons, skunks, foxes, and bats.
  
  Although the United States has been declared free from transmission of canine rabies virus variants, there is always a risk of reintroduction of these variants.2–6
  
  The virus is usually transmitted from animal to animal through bites. The incubation period is highly variable. In domestic animals, it is generally 3 to 12 weeks but can range from several days to months, rarely exceeding 6 months.7 Rabies is communicable during the period of salivary shedding of rabies virus.
  
  Experimental and historic evidence document that dogs, cats, and ferrets shed virus a few days prior to clinical onset and during illness. Clinical signs of rabies are variable and include inappetence, dysphagia, cranial nerve deficits, abnormal behavior, ataxia, paralysis, altered vocalization, and seizures. Progression to death is rapid. There are currently no known effective rabies antiviral drugs.
  
  The recommendations in this compendium serve as a basis for animal rabies prevention and control programs throughout the United States and facilitate standardization of procedures among jurisdictions, thereby contributing to an effective national rabies control program. ...
• Rosatte, Richard C., and Charles D. Maclnnes. "Relocation of City Raccoons1 Richard C. Rosatte and Charles D. Maclnnes2." In Ninth Great Plains Wildlife Damage Control Workshop Proceedings: April 17-20, 1989, Fort Collins, Colorado, vol. 171, p. 87. US Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, 1989.
• Schau, Michael. "Animal Law Research Guide." Barry L. Rev. 2 (2001): 147.
• Timm, Robert M. "House mice." (1994).
  Abstract The house mouse (Mus musculus) is a small, slender rodent that has a slightly pointed nose; small, black, somewhat protruding eyes; large, sparsely haired ears; and a nearly hairless tail with obvious scale rings. House mice are considered among the most troublesome and economically important rodents in the United States.
  
  Effective prevention and control of house mouse damage involves three aspects: rodent-proof construction, sanitation, and population reduction by means of traps, toxicants, or fumigants. The first two are useful as preventive measures, but when a house mouse infestation already exists, some form of population reduction is almost always necessary.
  
  Frightening: Ultrasonic devices have not been proven to control mice.
  
  Repellents: Ro-pel®, Moth flakes (naphthalene) not specifically registered, but may be of some value.
  
  Toxicants: Anticoagulant rodenticides (slow-acting chronic-type toxicants). Brodifacoum (Talon®). Bromadiolone (Maki®, Contrac®). Chlorophacinone (RoZol®). Diphacinone (Ditrac®). Pindone (Pival®, Pivalyn®). Warfarin (Final® and others). Toxicants other than anticoagulants (may be acute or chronic poisons): Bromethalin (Assault®, Vengeance®). Cholecalciferol (Quintox®). Zinc phosphide (Ridall Zinc®, ZP®).
  
  Fumigants: Practical use is limited to structures, containers, and commodities; for use only by trained personnel.
  
  Trapping: Snap traps. Live traps (Sherman-type, Ketch-All®, Tin Cat®, and others). Glue boards.
  
  Other Methods: Predators: dogs and cats are of limited value in some situations.
• Treves, Adrian, Robert B. Wallace, Lisa Naughton-Treves, and Andrea Morales. "Co-managing human–wildlife conflicts: a review." Human Dimensions of Wildlife 11, no. 6 (2006): 383-396.
  
  Abstract
  Conservationists recognize the need to work beyond protected areas if they are to sustain viable populations of wildlife.
  
  But ambitious plans to extend wildlife corridors beyond protected areas must consider the economic and political implications when wildlife forage on crops, attack livestock, or otherwise threaten human security.
  
  Traditionally, humans respond by killing “problem” wildlife and transforming wild habitats to prevent further losses.
  
  This traditional response, however, is now illegal or socially unacceptable in many areas, changing a simple competitive relationship between people and wildlife into a political conflict.
  
  Here we draw from experience in Bolivia, Uganda, and Wisconsin to outline a strategy for mitigating human–wildlife conflict based on participatory methods and co-management with twin objectives of wildlife conservation and safeguarding human security.
  
  Incorporating local stakeholders as partners in planning and implementation can help to win space for wildlife beyond protected area boundaries. We also show why systematic study of local people's perceptions of risk and participant planning of interventions are irreplaceable components of such projects.
• Vantassel, Stephen. Wildlife Damage Inspection Handbook, 3rd Ed., Website: https://www.lulu.com/shop/stephen-vantassel/wildlife-damage-inspection-handbook-3rd-edition/paperback/product-23891885.html
  
  Stephen M. Vantassel, CWCP, ACE Wildlife Control Consultant, LLC
  Blog: https://wildlifecontrolconsultant.com/
  Papers: https://kingsdivinity.academia.edu/StephenMVantassel
  Videos: https://www.youtube.com/channel/UCxP_IBhnqcgvX_aRM4f91nQ
  Podcasts: https://pestgeekpodcast.com/stephen-vantassel/
  Phone: 406-272-5323 Mtn Time Helping people resolve conflicts with wildlife through teaching, training, writing, and research
• Vantassel, Stephen M., Michael W. Fall, and Serge Lariviére. "Information Resources for Animal Control and Wildlife Damage Management." (2019).
  
  Abstract excerpts:
  
  ... the arrival of an invasive species, changes in building practices (e.g., egress windows, ridge vents), or the implementation of new regulations can confound traditional practices and require new control methods. Thus, it is important to provide a resource that provides detailed, updated and accurate information. ...
  
  The nuisance wildlife control industry has matured. The increased involvement of the private sector in wildlife control unleashed the creative forces of entrepreneurs in the development of new techniques and products.
  
  Until the mid-1980’s, most scientific information about wildlife damage management was scattered in articles in academic jounrals (e.g., Journal of Wildlife Management), “grey literature” (i.e., unpublished reports and conference proceedings), and government documents (i.e., U.S. Fish and Wildlife Service and Forest Service publications).
  
  Since then, wildlife damage management research has achieved greater prominence as demonstrated by the addition of new outlets and changes in publication policies.
  
  The emergence and rapid growth of the nuisance wildlife control industry has supported development of several trade magazines, association newsletters, listservs, bulletin boards, and numerous websites. ... we have highlighted important works to supplement the sources found in the various publications of the Wildlife Damage Management Technical Series.
  
  In addition, we have focused on information resources that are easily obtained, used primarily for the North American audience, and published since 1994. Materials from journals and other publications with restricted access are mentioned only when we believe the utility of the information justifies the effort involved to obtain them. The numerous websites referenced were checked for current access during October 2019.
• Vantassel, Stephen. Being Kind to Animal Pests. Lulu. com, 2017.
• Waer, Neil A. "Wildlife Management." Urban Wildlife Management (2005): 173.

...

Continue reading at INSECT INFESTATION / DAMAGE or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these articles on

Recommended Articles

• ANIMAL ALLERGENS / PET DANDER
• ANIMAL DAMAGE to BUILDINGS - home
• ANIMAL ENTRY POINTS in BUILDINGS - home
  • ANIMAL BITES & SCRATCHES - BATS
  • ANIMAL ENTRY POINTS - WHERE THEY GET IN
  • KEEPING ANIMALS OUT of BUILDINGS
  • CHIPMUNKS in the BASEMENT?
  • MOUSE in the HOUSE
  • OPOSSUM REMOVAL from BUILDINGS
  • RACCOONS in the ATTIC
  • SQUIRRELS in the HOUSE
  • FIND & REMOVE ANIMAL FECES & URINE
  • REPELLENTS for ANIMAL PESTS
• ANIMAL NOISES in BUILDINGS
• ANIMAL STAINS & MARKS in BUILDINGS
• ANIMAL or URINE ODOR REMOVAL
• ANIMAL or URINE ODOR SOURCE DETECTION
• BIRD DROPPING STAIN REMOVAL
• BIOLOGICAL POLLUTANTS
• BLACK STAINS from ANIMALS
• CARPET STAIN DIAGNOSIS
• CAT DANDER in BUILDINGS
• DOWNSPOUT DAMAGE from DOG CHEWING
• FIBER & HAIR IDENTIFICATION
• GOPHER HOLE DAMAGE
• GRAZING ANIMALS OVER SEPTIC SYSTEMS
• GROUNDHOG CONTROL
• INSECT INFESTATION / DAMAGE - home
• MICE in BUILDINGS, GET RID OF
• OPOSSUM REMOVAL from BUILDINGS
• RACCOONS in the ATTIC
• SQUIRRELS in the HOUSE

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