The short version
Coordinating a multi-unit spider inspection comes down to four things: a tenant notice that meets your state's entry rules, a route that covers every unit and common area in a day or two, a one-page log per unit, and a pro report that ties findings to a plan by unit. Spiders move between units through shared walls, chases and lit corridors, so inspecting a few units at random misses the source.
- Give written entry notice per your state and lease, usually 24 to 48 hours.
- Inspect every unit plus common areas, not just the ones that complained.
- Use one standard log per unit so findings can be compared across the building.
- Exterior lighting, utility rooms and storage areas are the usual shared sources.
- Require a pro report that lists findings and actions by unit number.
- Research: Glue traps are a monitoring tool as much as a treatment, and Local quotes vary; ask for a written estimate.
For property managers, landlords with more than a handful of units, HOA boards responsible for shared buildings, and maintenance supervisors asked to get spiders under control building-wide. It focuses on the coordination work that makes a pro's visit productive.
What to look for
Responding one complaint at a time is expensive and ineffective. Each visit is a trip charge, each treatment is a unit in isolation, and the shared source keeps producing spiders. A coordinated inspection costs more up front but produces a map of the building's spider pressure, a plan that addresses sources, and a dated record for every unit. Multi-unit spider problems are usually driven by a few shared conditions: bright cool-white lighting at entries and corridors that draws insects all night, cluttered utility and storage rooms, gaps around shared utility lines that let spiders move between units, and undisturbed attics and crawl spaces where webs accumulate for years. Tenants cannot see any of that. They see spiders in the bathroom and file a complaint.
- 1Complaints from units on the same stack or floor.
- 2Webs clustered at corridor lights and entry fixtures.
- 3Egg sacs in utility rooms, laundry rooms and storage cages.
- 4Spiders in vacant units at turnover.
- 5Web accumulation in attic access and crawl space hatches.
- 6Dark droppings on stairwell walls beneath lights.
Why it’s worth acting soon
- Complaints spread along shared walls and stacks.
- One-off unit treatments add up to more than a building-wide plan.
- Without notes on what you did, tenant disputes are harder to settle.
- Egg sacs in common areas hatch and reseed treated units.
- Vacant units become breeding sites between tenants.
in the U.S. are the black widow and brown recluseMedically significant spidersUS CDC Treatment options and typical costs
Tenant notice and scheduling
No cost: DIY step
Written notice to every unit with date, time window, purpose and preparation steps. Track responses, flag refusals, and confirm key access for no-shows per your lease and state law.
- Time
- Two to five days lead time
- Best for
- Meeting entry-notice rules and securing access
Building-wide inspection
$25–$75 per unit, often credited toward treatment
A technician walks every unit and common area with a standard checklist and a staff escort, logging findings by unit and taking photos.
- Time
- One to two days depending on unit count
- Best for
- Mapping where spiders actually are across the building
Common-area dewebbing and treatment
$200–$800 per building per visit
Dewebbing corridors, stairwells, entries and exterior eaves; egg sac removal in utility and storage rooms; perimeter application. Usually the highest-impact line item.
- Time
- Half a day
- Best for
- Removing the shared sources feeding individual units
Per-unit treatment
$50–$150 per unit
Crack-and-crevice application, web and sac removal, and monitoring boards in units the log flagged. Not every unit needs it, which is why the inspection comes first.
- Time
- 15 to 30 minutes per unit
- Best for
- Units with confirmed interior activity from the inspection
Sealing building gaps and lighting changes
$500–$3,000 depending on building size
Door sweeps on exterior and corridor doors, sealing shared utility penetrations, screening vents, and switching entry and corridor fixtures to warm bulbs or motion sensors.
- Time
- One to several days
- Best for
- Cutting long-term pressure at entries and utility penetrations
Prices are typical published ranges. Ask what’s included before you compare quotes.
Stacked boxes against a garage wall are a favorite hiding spot; check them before you move them.Notices, access and the inspection route.
Deliver it as your lease and state law require, typically posted and emailed, at least 24 to 48 hours ahead. Log delivery date and method per unit. Build a route sheet: unit number, planned time, key location, tenant response, and a blank for the result. Plan common areas into the route: entries, corridors, stairwells, laundry, utility and mechanical rooms, storage cages, attic and crawl space hatches, trash enclosures and the full exterior with every fixture. On the day, one staff member escorts the technician with the route sheet and a master key. A second handles tenant calls and reschedules. No-access units get a note and a second notice the same day. Aim to finish in one or two consecutive days so the report reads as a single snapshot. Start with the unit list and a site plan. Group units by building, floor and stack so the technician moves efficiently and findings can be compared along shared walls later. Write one notice for all units. State the date and a time window per floor, the purpose, that a technician and a staff escort will enter, and preparation steps: clear access to closets, under sinks, window sills and exterior walls; secure pets; do not remove webs. Cite the lease clause on entry.
The per-unit log and what to look for.
After the walk, lay the unit pages out by floor and stack. Patterns appear quickly: a column of moderate units above a heavy utility room, or every unit on a lit corridor showing entry-door webs. Those patterns are the treatment plan. Give the pro a copy of your logs alongside their own. Use one page per unit with the same fields every time: unit number, date, technician, escort, tenant present or not, and a checklist of locations: entry door, kitchen under sink and behind appliances, each bathroom behind toilet and under sink, each bedroom closet and window, living room corners, utility closet, balcony or patio, and the unit's exterior door light. For each location, record evidence type: live spider, web and its shape, egg sac, shed skin, droppings, or none. Add a size and color note for any spider and a photo reference. Flag any spider that could be a widow or recluse and note whether a specimen was collected. At the bottom, record the technician's rating for the unit: none, light, moderate or heavy, and a recommended action: no treatment, monitor, treat, or treat and exclude. Use a separate page per common area with the same structure and a fixture count for lit areas.
A vent that closes properly keeps spiders from using it as a winter doorway.From report to plan, and keeping the record.
Monitor only: light or no-activity units, checked again at the next visit or turnover. Price each tier separately so you can see the cost of the common-area work, which usually delivers the most improvement, versus the per-unit work. Ask for a recurring option covering common areas and exterior with unit visits on request. Tell tenants in a short building notice: inspection completed, treatment scheduled, what tenants can do, and how to report new sightings. Tenants who know there is a plan complain less and report more usefully. Keep everything in one building file: notices and delivery records, route sheets, unit logs, the pro report, service tickets and product labels. When a tenant disputes what was done, that file answers the question. Repeat the full inspection annually and compare unit ratings year over year. Require the company's report within a few days, with findings and a recommended action per unit and per common area, photos, and product names. Read it against your own logs and ask about disagreements. The plan should have three tiers. Building-wide: common-area dewebbing and sac removal, exterior perimeter application, and lighting and sealing changes at entries and utility penetrations. Targeted units: crack-and-crevice application and monitoring in units rated moderate or heavy.
What affects the price
- Number of units and floors.
- Whether inspection fees are credited toward treatment.
- Percentage of units with confirmed interior activity.
- Size and condition of common and utility areas.
- Attic, crawl space and roof access.
- Exterior fixture count and lighting changes.
When to call for help
Call a pro as soon as you have complaints from more than one unit, any complaint involving a suspected widow or recluse, or spiders in a vacant unit at turnover. Ask for a building-wide inspection with per-unit reporting rather than a single-unit callout. A good pro asks for a unit list, a site plan and your complaint history, and proposes a route and a time window. Ask how they log findings per unit, whether they photograph, how they handle no-access units, and what their report looks like. A good answer is a written report by unit number with findings, photos and a recommended action, plus a common-area section. Walking the corridors and spraying a few units is not an inspection.
What you can do yourself
Notices, scheduling, access, escorting, and the per-unit log are management tasks a pro cannot do for you. The coordination is your job and it is where most of the value sits. They also leave a written report from an outside expert, which tenants tend to trust. A pro is worth the fee for the inspection itself, because a technician who has seen a hundred buildings will find the chase or attic hatch feeding the third floor, and for treatment in units and voids with labeled products. Maintenance staff can also handle several of the resulting actions: warm bulbs in corridors and entries, door sweeps, clearing utility rooms and dewebbing common areas with a pole brush.
Simple ways to keep spiders away
- Switch all entry and corridor fixtures to 2700K or amber bulbs.
- Deweb common areas monthly with a pole brush and vacuum.
- Keep utility and storage rooms clear of cardboard and clutter.
- Install door sweeps on all exterior and corridor doors.
- Inspect and deweb vacant units at every turnover.
- Seal utility penetrations between units and into chases.
Under-sink cabinets get checked for gaps around pipes, which spiders and their prey both use.Did you know?
Cellar spiders, common in basements and utility rooms, are harmless to people.
Spiderlings disperse by ballooning on silk threads carried by air currents.
Widow webs feel noticeably stronger and stickier than house spider webs.
Questions people ask
How much notice do tenants need before a pest inspection?
Check your state statute and your lease, then give the longer of the two. Include date, time window, purpose and preparation steps, and keep a copy. It varies by state and lease. Many states require 24 hours written notice for non-emergency entry; some require 48 hours or reasonable notice.
Do we have to inspect every unit, or just the ones complaining?
Spiders move through shared walls, chases and corridors, and the source is often a unit or common area with no complaints because nobody is home or nobody minds. Complaint-only inspections miss the source and lead to repeat callouts. Inspect every unit.
What if a tenant refuses entry for the spider inspection?
Note the refusal, offer another time, and mark the unit as not inspected. If the unit is a suspected source, escalate under the lease terms. Do not stall the rest of the building. Follow your lease and state law. Most leases allow entry with proper notice for pest control.
What should a multi-unit spider inspection report include?
A section per unit with findings, photos, evidence type and a recommended action; a common-area section covering corridors, utility rooms, storage, attic and exterior; a list of no-access units; product names for anything applied; and a proposed plan with per-unit and building-wide pricing.
How should tenants prepare for a spider inspection?
Ask them not to clean webs beforehand, since webs and egg sacs are the evidence the inspection needs. Include this in the notice. Ask them to clear access to closets, under sinks, window sills and the space behind furniture along exterior walls, and to secure pets.
How often should a multi-unit building be inspected for spiders?
Once a year building-wide, ideally late summer when activity peaks, plus every vacant unit at turnover and monthly common-area checks by maintenance. Buildings with confirmed widow or recluse populations warrant more frequent unit checks until the log shows a sustained decline.
How much does spider extermination cost?
Get an inspection first, since the severity rating a technician assigns is what moves you between brackets. It's a published estimate, not a local quote. Local quotes vary; ask for a written estimate.
Was it really a spider bite?
If a sore is spreading, warm or draining, treat it as a possible infection and see a doctor rather than assuming a spider. Treat it as a rough guide, not a local count. Probably not. In Suchard's study of 182 patients who came to one California emergency department with a suspected spider bite between January 2006 and November 2007, published in 2011, only 3.8% were diagnosed as spider bites, while 85.7% were diagnosed as infections, most often skin infections.
Sources (6)
The facts in this article come from the public sources listed above. Every home is different, so ask the company you talk to about pricing and what’s included. Published by Spider Exterminator · Updated September 11, 2026 · How we write these guides