Before you can determine if there is a problem or contemplate solutions, you must conduct a thorough inspection. With information from an inspection, an experienced observer can provide management options for problems associated with uninvited animal guests.
Steps to an Inspection
The major steps in the process are preparation, contact interview, inspection, and recommendations. The specifics depend on the type of building and the animals involved. Brief descriptions of signs and problems associated with the animals that commonly enter structures are included in Appendix A.
Use a site map and an inspection form. A site map is usually a floor plan of the building. A generic inspection form, such as that found in Appendix B, is applicable to most structures and animals. Inspection forms could also be developed that are specific to a particular location, such as a certain school building, or to a particular animal (Appendix C).
If someone who is not on site daily is inspecting the building, that person should interview an appropriate contact, such as a facility manager, custodian, or kitchen staff member.
In the interview, ask either general or probing questions. A general question might be, "Please describe what you know about the problem," or "Have you noticed any problems?" This type of question provides an opportunity for the contacts to give their perspective, can lead to probing questions, and may guide where to start the inspection.
Probing questions focus on specific information. They may address any of the following: noises; sightings of animals or signs; odors; time of day of animal activity; frequency of activity; and health concerns, such as contacts between wild animals and humans or pets. Occasionally respondents misinterpret mechanical sounds (smoke alarm with low battery, swaying utility line, etc.) as animal noises. Probing questions can help to determine the likelihood of this error.
The most important piece of inspection equipment is a good flashlight. Other helpful equipment:
- extendible mirror for viewing less accessible locations
- stepladder for interior inspections
- larger ladders for exterior inspections
- binoculars for tall structures
- ultraviolet light source for detecting rodent urine stains
- animal identification books, including those that show mammal tracks and droppings
Safety equipment includes respirators (preferably with a HEPA filter); goggles and kneepads for when you inspect crawl spaces; disposable gloves; safety helmets; bungee cords or other means of securing ladders for use; and safety ropes/harnesses.
Follow appropriate safety precautions throughout the inspection by paying attention to equipment and being aware of potentially harmful situations. Keep ladders in good repair and choose ones of appropriate construction and height for the work that needs to be done. Secure them so that they will not accidentally fall over, and use safety helmets to prevent head injuries and possible death. When climbing steep roofs, you may need safety ropes and harnesses.
Respirators are necessary for the safe inspection of most crawl spaces. HEPA filters, which filter out small particles such as hantavirus, are recommended. Goggles, disposable gloves, and coveralls provide additional personal protection. Consult the Occupational Safety and Health Administration (OSHA) guidelines for safety practices on ladders, the use of respirators and other equipment, and any other health or safety concerns.
Whether you should focus on the interior or exterior for your inspection will depend on what you are looking for. For example, the presence of raccoons or squirrels can often be determined by an outside inspection, and an inside inspection may not be needed. On the other hand, interior inspections for bats, mice, or rats can help focus the exterior inspection for entry holes. What you may be looking for (such as entry hole sizes and probable locations) will vary according to species.
Whether inspecting interiors or exteriors, look for and record current, past, and potential problems on the inspection form and site map. Note entry holes, fecal droppings, runways (such as in insulation), tracks, rub marks, urine stains, gnaw marks, food caches, nests, odors, noise (vocalizations, movements), evidence of past control efforts (such as empty pesticide containers or old repairs), burrows, access routes, carcasses, and live animals. Note any structural sites that currently do not have problems but are vulnerable to future access or damage by animals.
Interiors. Inspect the building systematically. Work your way from the top of the building to the bottom. Within each room, move either clockwise or counterclockwise. Pay particular attention to room corners and underneath and behind furniture. If suspended ceilings are present, push up the panels in several locations to check above the ceiling. Inspect attics, basements, closets, built-in drawers, areas underneath sinks, plumbing/utility accesses, and miscellaneous crawl spaces.
Exteriors. Outside, thoroughly inspect the foundation, then repeat the inspection on the upper portions of the structure. Be sure to check areas beneath decks, crawl spaces, dumpsters, garbage storage areas, piles of firewood, lumber, or debris. Inspect garages, eaves, dormers, windows, architectural returns, vents, drip edges, soffits, chimneys, roof corners, and roof tie-ins.
Recommending Management Options
Using the findings of the inspection, recommend management options, in writing, to the contact person. Four possibilities are animal removal, exclusion/repair, prevention of future problems, and monitoring (see Appendix B). Techniques for animal removal include capture, one-way doors, repellents, and pesticides. Exclusion generally refers to the closure of entry sites to prevent reentry by animals. If monitoring for vertebrate problems is feasible, describe where the monitoring should be done and the techniques to be used. Possible techniques include glueboards, tracking stations, and traps. Explain when to check the monitoring stations.
Discuss the inspection results and management recommendations with the contact person. Show photographs of on-site situations that are difficult to see. A photo album of structural problems, typical animal damage, management options, and prevention techniques can also be an important resource.