The presence of wildlife in a home’s basement, attic, or elsewhere is something that all inspection personnel should be prepared for. In order to perform the best inspection possible, inspectors should know what signs to look for in the case of all variety of common and not so common animals that can invade a home.
As one of the most likely creatures to infiltrate a home, the presence of mice can be a sign of other possible wildlife infiltrations. Things like bird feeders, acorn trees and other sources of food can be an invitation to a number of different creatures. So too can woodpiles or other brush and debris piles, regardless of their proximity to the home.
When it comes to looking for openings made by small wildlife creatures, the size of the hole can provide clues to the type of creature. Mice need at least a 1/4-inch opening while squirrels require holes from 1.5-inches to three inches. Bats and birds fall in the middle as they need at least a 3/8-inch to one-inch circumference gap. Hole sizes do not definitively identify the species of animal, so droppings can be another clue as to what has infiltrated the home.
Bat droppings, which are usually black and brown speckles, will be concentrated below where they roost and crumble like dust when disturbed. Birds often leave the tell-tale white droppings where they enter while mice leave rice-seed type droppings scattered about. Squirrels on the other hand may or may not leave droppings.
It’s best to start an inspection for holes from the outside using a powerful flashlight since the hole will not reflect the light. Pay special attention to corners, gables, eaves and vents, and any place where two boards meet. These are the areas where moisture and heat can cause the boards to expand and contract until a gap forms that animals can exploit.
Since many animals like squirrels, mice, raccoons, and chipmunks can enter at ground or foundation level, you should inspect the foundation on your knees and look for gaps around pipes and dryer vents. Rotted sills and cracks in the foundation can also be infiltration points for smaller creatures like mice.
Many infiltration points will have telltale fur or rub marks where oil from the animal’s body discolors the area around the opening. Be sure to check downspouts and gutters as they can show the signs of where squirrels and raccoons have climbed. Raccoon prints will look like brown smears and scratches will be deep and pronounced. In addition, be sure that all hatchways and garage doors fully seal without any openings where animals can get in.
When moving to the roof, begin by scanning the gutter and roof area as normal while keeping an eye out for anomalies that could be infiltration points for animals. Squirrels for instance, are known to sit on the gutter and chew through rain-softened fascia boards. The roof itself could have telltale signs of feces such as that of raccoons that often defecate before entering an attic or chimney. In order to avoid contact with feces, its best to wear protective gloves as many forms of animal feces carry potentially dangerous bacteria, microscopic creatures and roundworms.
Moving to the chimneys and starting from the top, check the flue (or flues) for proper regulation screens and make note of any rust or holes. Uncapped flues should be inspected for smudge marks and fur (which suggest raccoon presence) and spider webs (which suggest lack of activity). Take an extra moment to be quiet and listen for any noises emanating from the chimney such as scratching, fluttering, chirping, or grinding noises.
After a thorough inspection of the exterior and roof of the house, it’s time to move to the inside with particular focus on the attic and crawl spaces. Once again, it is best to wear proper protection such as a HEPA filter dust mask, heavy gloves, knee pads and thicker clothing to protect yourself from touching or inhaling animal feces. This also protects you from common inspection dangers like dust and insulation fibers.
Using proper precautions to walk on the beams and using the trusses for greater stability when possible, inspect the vent screens for areas where they have been pulled away. Turn off the flashlight to inspect for any light that may be entering from holes while being sure to differentiate between them and ridge vent openings or soffit vents.
The insulation itself can hold clues to animal infiltration as holes in the insulation can be caused by animals. Trails in blown and loose fiberglass insulation can be the signs of animal trails that can range from slight to very pronounced, depending on the animal.
Feces can also be present on top of and under the insulation.
Lastly, look for signs of the homeowner adding things that are meant to block infiltration as this usually means that it has occurred in the past. This can include aluminum flashing at the eave level, hardware cloth over vents, mouse poison, wire screening around porches and decks etc.
Today’s home inspectors have a long and growing list of things to look for when inspecting a house. Although these items regarding animal infiltration add to that list, those that desire to do the best possible job will incorporate them into their investigative techniques.