A record format that works on paper or a phone
Use one line per finding with six fields. Date. Location, as specific as you can: master bath, behind toilet, floor level. Evidence type: spider, web, egg sac, shed skin, droppings. Description: size compared to a coin, color, markings, and for webs the shape and whether it is dusty or fresh. Photo filename. Action: vacuumed, left in place, captured. Add a second section for the exterior with the same fields, noting the side of the house and the nearest fixture, door or vent. A few descriptions do most of the identification work. A flat circular web with spokes outdoors is an orb weaver, harmless. A messy tangle in a ceiling corner is a house spider or, with very long thin legs, a cellar spider, both harmless. A sheet with a funnel into a crack is a funnel weaver, harmless. A strong, irregular, sticky web low in a dark corner with a shiny black spider hanging upside down is a widow. Fast-running spiders with no web are usually wolf spiders or, in the south-central states, possibly recluses. Date every entry. The pattern over weeks is what matters.
Where to look during the inspection walk
Indoors, start at the lowest level. In basements and crawl spaces, check ceiling joists, the sill plate where the foundation meets the framing, behind stored items and around pipe penetrations. Garages: the door frame corners, behind and under shelving, inside rarely used boxes, and around the water heater. Ground floor: window tracks, behind the toilet, under sinks, behind the refrigerator and washer, and the top corners of closets. Upper floors and attics: closet corners, the attic hatch, and around recessed lights. Outdoors, walk each side. Look at eaves and soffit corners, every light fixture, the meter box and utility penetrations, window wells, deck undersides, firewood, and anything stacked against the house. Bring a flashlight even in daylight and shine it at a low angle across surfaces; silk shows up far better in raking light. A small mirror helps under sinks and behind appliances. Do not clean as you go on the first walk. Record everything first so you have a true baseline, then vacuum webs and sacs afterward and note on each line that you removed it.
Using the record with providers and after treatment
Send your log and best photos to two or three providers before anyone visits. Ask each the same questions: which findings concern you most, what would you look for that I may have missed, and how will your plan address the rooms on the list. Good answers name your rooms and evidence: the sill plate findings suggest entry from the exterior, or the closet sacs mean an indoor population that needs crack-and-crevice work, not just a perimeter spray. Ask for the provider's own inspection findings in writing and staple them to your log. If they found sacs in an attic you did not check, that is useful. If they list rooms you inspected closely and found nothing, ask what they saw. After treatment, keep logging in the same format for at least two months and count sightings per week in each room. A working plan shows a steady decline in the rooms that were worst. A plan that is not working shows the same rooms at the same rate, and your log gives you a clear basis for a follow-up call or for switching providers. Property managers should keep one log per unit and one for common areas.
The research on spiders in U.S. homes
No agency publishes a single national spider infestation rate, and this page does not invent one. What exists is survey data and published pricing benchmarks, summarized below with their limits stated plainly. Forty percent of the 50 North Carolina homes inspected by Bertone and colleagues in 2012 had wolf spiders, a presence finding from a small volunteer sample rather than a national prevalence rate for these large, ground-hunting spiders. A small spider that turns to watch you is almost certainly a harmless jumping spider: Bertone and colleagues found them in 50% of 50 North Carolina homes in 2012, a presence figure from a small sample rather than a national rate. If the spiders in your corners have thin bodies and very long legs, they are probably cellar spiders: Bertone and colleagues found them in 84% of 50 North Carolina homes in 2012, a presence finding from a small regional sample. Bertone and colleagues, inspecting 50 North Carolina homes in 2012, found spiders in 92.6% of the 54 basements they searched, the highest room-level rate in the study; it measures presence, not infestation, in one regional sample. A majority, 57%, of respondents reported using store-bought pest-control products in ConsumerAffairs' February 2024 survey of 2,000 U.S. respondents, a self-reported survey that combined pest and mold questions and describes general consumer behavior rather than the infestation rate for any one pest. Use these numbers as context, not as a diagnosis. A provider's written inspection findings should drive the treatment plan, and any quote should spell out how many visits, which areas and what follow-up it covers.