A thorough pest inspection covers the full exterior and interior of a home, checking for entry points, moisture problems, signs of active infestations, and conditions that attract pests in the first place. Whether you’re buying a home, selling one, or just staying ahead of problems, knowing exactly what gets checked (and what to look for yourself) puts you in a much stronger position. Here’s a detailed breakdown of every area and sign that belongs on a pest inspection checklist.
Exterior: Foundation to Roofline
A professional inspection starts outside, following the foundation and working upward. The foundation perimeter is where most pest problems begin. Inspectors look for cracks, gaps, mud tubes, damaged siding, and any condition that gives pests a path to the structure. Even a hairline crack in a concrete foundation can serve as an entry point for ants and termites, while mice can squeeze through openings as small as a dime and rats through holes the size of a quarter.
From the foundation, the inspection moves up to soffits, fascia, eaves, window trim, and roofline transitions. These are common entry zones for wasps, bats, squirrels, and carpenter bees. Inspectors look for openings, nests, droppings, damaged wood, and evidence that insects or rodents are using the exterior as a route indoors.
Two exterior conditions matter as much as the structure itself:
- Vegetation contact. Shrubs, vines, and dense growth touching the foundation or siding act as bridges for ants, spiders, and rodents. Branches touching the roofline give squirrels and rats direct access to the attic. A buffer of at least a foot between plants and the house is the standard recommendation.
- Drainage and standing water. Water that collects near the foundation supports moisture-loving pests like termites, carpenter ants, and mosquitoes, and it weakens wood and other building materials over time. Grading should slope away from the house, gutters should drain well clear of the foundation, and no puddles should linger after rain.
Basement and Foundation Interior
Basements often reveal the earliest signs of pest activity because they sit closest to the soil and tend to trap moisture. A complete basement check covers:
- Rodent droppings. Rat droppings are roughly three-quarters of an inch long with blunt ends. Mouse droppings are about a quarter inch with pointed ends. Finding either along baseboards, near stored boxes, or under shelving signals an active or recent problem.
- Moisture and water stains. Damp walls and floors attract termites, carpenter ants, silverfish, and centipedes.
- Mud tubes along foundation walls. These pencil-sized tunnels made of soil are the hallmark of subterranean termites traveling between the ground and wood in the structure.
- Carpenter ant frass. Fine, sawdust-like material pushed out of wood galleries where carpenter ants are nesting.
- Chewed insulation or wiring. Rodents gnaw through insulation to build nests and chew wiring, which creates a serious fire hazard.
- Gaps around pipes. Visible entry points where plumbing or wiring penetrates the foundation are easy highways for ants, mice, and cockroaches.
Kitchen, Bathrooms, and Utility Rooms
Pests are drawn to food, water, and warmth, which makes kitchens, bathrooms, and laundry areas high-priority zones. Under every sink, check for leaks. Even a slow drip provides enough moisture to sustain a cockroach colony or draw ants from across the house. Behind appliances like refrigerators, stoves, and dishwashers (if visible), look for droppings, grease marks, or dead insects.
Plumbing penetrations deserve special attention. Wherever a pipe passes through a wall or floor, there’s often a small gap around it. These gaps are some of the most common indoor entry points for pests. Pantry corners, especially behind rarely moved items, should be checked for moth larvae, beetle activity, or rodent droppings. Utility rooms with water heaters or HVAC units are similarly attractive to pests because they offer warmth and occasional condensation.
Attic and Crawl Space
These hidden spaces can quietly develop serious problems that go unnoticed for months or years. Attics and crawl spaces should be checked for:
- Droppings, nesting materials, or chewed wood and wiring
- Moisture stains or damp, compressed insulation
- Musty odors or poor ventilation
- Visible mold or mildew growth
- Entry points where pests or moisture are getting in, such as gaps at vent screens, around ductwork, or where the roof deck meets the wall
Disturbed or displaced insulation is a telltale sign of rodent or wildlife activity. Raccoons, squirrels, and rats all tunnel through attic insulation to nest. If you hear scratching or scurrying at night, the attic is the first place to investigate.
Signs of Termites
Termite damage gets its own focus because it’s both common and expensive. The physical signs vary depending on whether you’re dealing with subterranean termites (which come up from the soil) or drywood termites (which infest wood directly without soil contact).
Subterranean termites leave mud shelter tubes, typically running along foundation walls, piers, or plumbing. Drywood termites leave frass: small, pellet-shaped droppings that look like coarse sawdust and often accumulate in small piles beneath infested wood.
Other signs that apply to both types:
- Hollow-sounding wood. Tap exposed wood with a screwdriver handle. A hollow sound suggests termites have eaten away the interior while leaving the surface intact.
- Discarded wings. Small, paired wings found near windowsills or light sources, especially in spring, indicate a recent termite swarm.
- Buckling or spongy floors. Damage to subfloor joists causes flooring to sag underfoot.
- Bubbling or peeling paint. Moisture from termite activity behind walls causes paint to blister.
- Tight-fitting doors and windows. Termite damage warps wood frames, making them stick.
- Pinpoint exit holes in drywall. Drywood termites occasionally push through drywall, leaving tiny holes.
Signs of Rodents
Rodent evidence is usually easier to spot than termite damage, but it’s also easier to underestimate. Beyond droppings, look for dark grease or dirt marks along walls and floorboards. Rodents follow the same paths repeatedly, and their oily fur leaves rub marks that darken over time. These tracks are especially visible along baseboards in basements and attics.
Gnaw marks on wood, plastic, or even lead pipes indicate active chewing. Nesting materials like shredded paper, cotton, fabric scraps, or pulled-apart insulation tucked into dark, secluded corners confirm an established colony rather than a passing visitor. A distinct musky or stale odor, particularly in enclosed spaces, often accompanies a rodent infestation even before you find physical evidence.
Tools Professionals Use
Licensed inspectors carry tools that go beyond what a homeowner can do with a flashlight and screwdriver. Moisture meters detect elevated moisture levels inside walls and wood, pinpointing conditions that attract termites and carpenter ants before visible damage appears. Thermal imaging cameras are increasingly common for non-invasive inspections. They detect heat signatures from nests inside walls and identify moisture patterns associated with termite damage, all without cutting into the structure. Higher-resolution thermal cameras are typically needed for termite work, while entry-level models can spot larger heat sources like rodent nests.
Borescopes (small cameras on flexible cables) let inspectors see inside wall cavities, behind siding, and inside crawl space areas too tight to physically enter.
Red Flags That Demand Immediate Attention
Not every finding on a pest inspection carries the same weight. Some are maintenance items. Others are urgent. Foundation damage tied to pest activity is at the top of that list. Foundation repairs alone can cost between $5,000 and $40,000 depending on severity, and pest-related wood damage to structural members can push those numbers higher.
A confirmed termite infestation is always a red flag, regardless of how minor it looks on the surface. Termites work from the inside out, so visible damage typically represents far more destruction hidden within the wood. If you’re buying a home and the inspection report flags termites, the standard approach is to negotiate treatment and repair costs with the seller or get an independent assessment of how far the damage extends before finalizing the purchase.
Roof damage that creates pest entry points is similarly urgent. Leaks attract moisture-dependent insects and give wildlife easy access to the attic, compounding the original problem quickly.
How Often to Schedule Inspections
Industry guidelines generally recommend professional pest inspections on a quarterly or annual basis, depending on your region, the age of your home, and your pest history. Homes in termite-prone areas (the Southeast, Gulf Coast, and parts of California, for example) benefit from annual termite inspections at minimum. For general pest control in a typical 1,500-square-foot home, a one-time professional visit runs roughly $300 to $550, while quarterly service plans range from $100 to $300 per visit.
Even between professional visits, walking your own checklist twice a year, once in spring and once in fall, catches early signs before they become entrenched problems. Focus on the high-priority areas: foundation perimeter, basement, kitchen, and attic. The earlier you spot droppings, mud tubes, or new entry gaps, the simpler and cheaper the fix.