How to Score Your Home's Infestation Risk Honestly

A checklist is only as useful as the honesty of the answers going into it. Our Infestation Risk Checklist does the arithmetic for you, but the arithmetic can't correct for a homeowner who unconsciously grades their own house on a curve, in either direction. Understanding exactly how the score is built is the best defense against doing that without realizing it.

Why a scored checklist beats a gut feeling

The value of running conditions through a fixed scoring formula rather than eyeballing "does my house seem risky" is that it removes the two things human judgment is worst at here: weighting several small factors against each other consistently, and staying calibrated over repeated checks. A person glancing around a basement tends to anchor on whichever single thing is most visually obvious in the moment — a water stain, a pile of boxes — and either over- or under-weight everything else relative to it. A fixed formula applies the same weight to the same factor every time, on every room, on every visit, which is precisely the kind of consistency that's hard to hold onto by memory alone.

The eight factors and what they're worth

The checklist scores eight yes-or-no conditions, each carrying a weight from 1 to 3 points, for a maximum possible score of 17. Two factors carry the top weight of 3: damp basement, crawl space, or plumbing leaks, and visible cracks or gaps around the foundation, pipes, or utility lines. Five factors carry a middle weight of 2: wood-to-soil contact, food debris left out, cardboard clutter in storage areas, standing water in gutters or plant saucers, and firewood stacked against the house. One factor carries the lowest weight of 1: older or slightly decayed exterior wood. The weights aren't arbitrary — they reflect how directly and broadly each condition draws pests in, which is exactly why the two highest-weighted factors are the two that show up as root causes across nearly every species covered elsewhere on this site, from termites to silverfish to cockroaches.

Worked examples across the full range

Running real answer combinations through scoreInfestationRisk() shows how the bands actually work. Answer every question false and the score is 0 out of 17 — Low, with no recommendations returned, since none apply. Check off just moisture issues and exterior gaps — the two highest-weighted factors, nothing else — and the score is 6 out of 17, landing in Moderate with two recommendations. Add wood-to-soil contact, food debris, and cardboard clutter to that same list and the score climbs to 12, crossing into High with five active recommendations. Check off literally everything and the score reaches the full 17, Severe. For comparison, checking only the lowest-weighted single factor — old, untreated exterior wood, and nothing else — scores just 1 point, staying comfortably in Low despite technically being a "yes" answer. The gap between a 1-point Low score and a 6-point Moderate score, both built from checking boxes that are individually true, is exactly why the weighting matters more than the raw count of "yes" answers.

Why moisture and exterior gaps carry the top weight

These two factors dominate the score because they show up as contributing conditions across the widest range of species, not because they're inherently scarier than the others. Damp conditions draw in silverfish, are cited by name in the termite catalog entry's structural note, and favor powderpost beetle activity in wood with elevated moisture content. Exterior gaps are the literal entry mechanism for the fall overwintering surge — boxelder bugs, cluster flies, stink bugs — and for wood-to-soil pests looking for a bridge indoors. A single fix to either one touches a wider range of potential problems than a fix to any of the lower-weighted factors does on its own, which is precisely what a 3-point weight is meant to signal: address this first, not because it's the scariest-sounding item on the list, but because it's doing the most structural work in the score.

The honesty problem, both directions

Self-assessment checklists fail in two opposite ways, and it's worth naming both rather than guarding against only the one that feels more likely. Denial bias shows up as rounding a "yes, but it's minor" answer down to "no" — a foundation crack you've been meaning to look at, dismissed as not really counting because nothing's obviously come through it yet. Overreaction bias shows up as the opposite: checking every box that could conceivably apply out of general anxiety, inflating a genuinely Low or Moderate situation into a Severe-sounding one that then gets treated with more urgency than it warrants. Both failure modes produce a number that doesn't reflect your actual home, just in opposite directions, and both are corrected the same way — answer each condition as a literal yes-or-no fact you could point to and show someone, not as a feeling about how worried you are.

Why the band boundaries sit where they do

The four bands aren't evenly spaced by score — they're spaced by percentage of the 17-point maximum, which matters once you understand where the cutoffs actually fall. Low covers 0 to 20% of the maximum score, Moderate runs from just above that to 45%, High extends to 75%, and anything above that is Severe. In practical terms, that means it takes checking off roughly a fifth of the total weighted risk before the checklist stops calling a home Low, and it takes crossing three-quarters of the total weight before Severe kicks in — a deliberately conservative design that resists both the "one gap means doom" overreaction and the "it's just one thing" dismissal, since either extreme genuinely does require several factors stacking together to move the band.

Same total score, different underlying picture

It's worth knowing that two very different homes can land on the identical score, which is exactly why the recommendations list matters more than the number alone. A home with only moisture issues and exterior gaps checked scores 6 points — two high-weighted factors. A different home with food debris, cardboard clutter, and standing water checked, but no moisture or gap issues at all, also scores 6 points — three mid-weighted factors instead. Both land in the identical Moderate band with the identical score, but they call for genuinely different next steps: the first home's fix is a dehumidifier and some caulk, the second's is closer to a general cleanup and drainage check. Reading the returned recommendation list, not just the headline number, is what actually tells you which situation you're in.

Re-scoring after you fix something

Because the checklist reflects current conditions rather than a fixed property trait, it's worth treating a score as a snapshot to revisit rather than a one-time verdict. Fixing the two highest-weighted factors on a Moderate 6-point score with nothing else checked drops it straight to 0 and Low, a bigger swing than fixing any three lower-weighted factors would produce. Pairing a re-check with a seasonal trigger — before the fall gap-sealing window, or after a spring wet season — keeps the score meaningfully current instead of reflecting conditions from months earlier that may have already changed in either direction.

What the score is not

It's worth being precise about what this checklist measures, since it's narrower than "do I have bugs." The score is a susceptibility measure — how many of the conditions that typically invite pests indoors are currently present — not a detection tool and not a diagnosis of an active infestation. A home can score Severe with zero bugs currently present, because the conditions that would eventually invite them just haven't been discovered by anything yet; a home can also score Low while still having an isolated existing problem the checklist's eight factors don't happen to capture. Our Trap Spacing Calculator and monitor traps are the tools for detecting actual current activity; this checklist is specifically about the conditions that make future activity more or less likely.

Turning a band into an actual response

Each band implies a different pace, not a different type of action — the recommendations themselves are the same prevention steps regardless of band, just more or fewer of them apply at once. Low means the highest-value opportunistic fix is worth doing when convenient, with no particular urgency. Moderate means picking the one or two highest-weighted flagged items and addressing them within the next few weeks is a reasonable pace. High means enough conditions are stacked together that prioritizing the full recommendation list over the next month is worth the effort, starting with whichever factors carry the most weight. Severe means addressing the highest-weighted items — moisture and exterior gaps, if either is flagged — as soon as practically possible, since multiple compounding conditions are present at once rather than just one or two isolated ones.

Scoring your own home

Our Infestation Risk Checklist runs this exact weighted logic against whichever conditions you check off, returning a score, a band, and the specific recommendations tied to what you flagged — useful as a planning tool as long as the answers going in are literal facts about your home rather than a reflection of how worried you happen to feel that day.