Burrowing Rodent and Exterior Program

Purpose

Exterior rodent work fails because nobody measures it. A tech drops bait at holes, comes back a month later, sees holes, and drops more bait, and the account never learns whether the population moved. The plug test fixes that for the cost of a walk: plug every opening, come back on a stated window, count what reopened. That number, not the tech's impression, picks the method and proves the program works.

This SOP also guarantees that a burrow running under a footing gets referred rather than filled, and that nobody on a residential route reaches for a burrow fumigant next to an occupied house.

Scope

Covers burrowing rodents on residential and small commercial exteriors: Norway rats, ground squirrels, pocket gophers and voles, plus the harborage and food sources that support them.

Does not cover bait station install and servicing, owned by the rodent bait station SOP, which this procedure calls into. Structural sealing is the rodent exclusion SOP, grade and moisture correction are the moisture and conducive condition report, and any animal requiring a wildlife permit is the wildlife exclusion SOP. Burrow fumigants are excluded outright at step 5.

Roles and responsibilities

Procedure

Step 1 - Name the animal before you pick a method, because the label and the law fork on it. Read the opening and the spoil: a Norway rat opening runs roughly 2 to 4 inches across with a smooth packed apron and a run leading away, a ground squirrel opening is wider with a loose fan of soil, a gopher leaves a crescent mound over a plugged hole, a mole leaves a raised tunnel ridge. Acceptance: species written on the ticket with the two cues that support it, and confirmation that the product you intend to use names that species on its label. Wrong looks like a gopher bait applied to mole tunnels, which is ineffective and is use inconsistent with the labeling, since moles are insectivores rather than rodents and most rodent baits do not list them. Stop rule: openings you cannot attribute, nothing is applied and the service manager reviews photographs. Hazard: a ground-nesting yellowjacket entrance looks like a small burrow at ten feet, so nothing goes near an opening with insect traffic, and a disturbed nest means everyone withdraws upwind and the stinging insect SOP takes over.

Step 2 - Map and number every opening, and screen each one for structural involvement. Walk the whole exterior including under decks, along fence lines and behind detached structures, flag and number each opening on a site sketch, and measure the distance from each to the nearest footing, slab edge or stoop. Acceptance: every opening numbered with a photograph, a measured distance to the nearest structural element, and a zone assigned so the count can be read by area later. Wrong looks like a count taken from the driveway that misses the six openings behind the shed, which then repopulate everything you treated. Stop rule: any opening within 3 feet of a footing, at a slab edge or under a stoop is not plugged, filled or dug, is photographed with its measurement, and goes to the service manager as a structural referral the same day, because backfilling a void under a footing hides settlement. Hazard: reaching into an opening puts a bare hand where a snake, a spider or a skunk may be, so probing is done with a rod at arm's length, and a burrow with an occupant you cannot identify is left alone and photographed.

Step 3 - Get the utilities located before anything is dug, driven or probed deep. File the 811 one-call ticket for the address, wait the state's required notice period, and walk the marks with the customer, asking about private irrigation, gas grill and lighting lines, which one-call does not locate. Acceptance: ticket number on the job record, marks present on the ground, and any private line either located by the customer or treated as unknown and hand-dug. Wrong looks like a stake driven for a trap anchor through an irrigation lateral; stop rule, marks not present or the notice period not elapsed and nothing gets driven or dug that day. Hazard: if a line is struck, nobody tries to plug or crimp it, everyone moves upwind away from the site, no engine is started and no phone is used at the line, and 911 and the utility are called from a distance; for a gas line that distance is the far side of the street and the household comes out with you.

Step 4 - Plug every mapped opening and set the recheck window. Pack each opening with loosely crumpled paper pushed in by rod, then cap it with a handful of the site's own soil tamped flush, so a reopen is unambiguous rather than a judgment call about whether a hole looks fresher. Acceptance: every mapped and non-referred opening plugged and ticked off, plug material visible in the photograph, and the recheck booked at the shop default of 48 hours after plugging, tightened to 24 where rain would wash the plugs. Wrong looks like plugs made of gravel or expanding foam, which a rat pushes aside without leaving a legible reopen. Stop rule: a plug that will not seat because the opening runs under hardscape gets logged as unpluggable with a photograph rather than forced. Hazard: kneeling at burrow openings puts hands and knees in soil carrying rat urine, which transmits bacterial infection through cuts and mucous membranes, so nitrile gloves and knee protection stay on, cuts are covered before the visit, and hands are washed before eating or touching the face.

Step 5 - Count the reopens, and let that number pick the method. At the recheck, count openings that reopened or show fresh spoil, divide by the number plugged, and record both figures. Acceptance: an activity rate stated as reopened over plugged, with each reopened opening carrying a method - a trap at the opening, a tamper-resistant station per the bait station SOP, or harborage work at step 6. Wrong looks like bait scattered at every hole regardless of whether it reopened, which feeds the survivors and burns the label rate on inactive ground. Stop rule: a reopened burrow whose occupant is not confirmed rodent stays untreated pending the wildlife referral. Hazard: burrow fumigants, including aluminum phosphide products that generate phosphine on contact with soil moisture and cartridge products that generate carbon monoxide, are not used under this procedure at any residential or semi-commercial site, because the gas travels through soil and enters the structure through the same voids the burrow follows; they are restricted use, and their labels carry a buffer around occupied residential buildings stated as a distance in feet, so read the label in hand and confirm applicator certification before anyone considers them on open ground.

Step 6 - Take away what made the burrow worth digging, in writing. List every harborage and food source with its location: woodpiles on soil, dense ivy or juniper against the foundation, stored lumber, unsecured trash, spilled bird seed, pet food left out, fallen fruit and pet waste. Acceptance: a written list handed to the customer with each item located, an owner named for each, and a target date, with shop-performed items separated from customer-owned ones. Wrong looks like a verbal mention of the woodpile that never appears on paper, so the account cancels in three months believing the program failed. Stop rule: the customer declines an item, log the refusal with the date and adjust the cadence rather than carrying the same recommendation forward silently. Hazard: moving a woodpile that has sat on soil puts hands into spider and snake habitat and lifts accumulated droppings into the air, so it is moved top down with gloves and a rod rather than bare hands, and heavy droppings are wetted first per the attic rodent cleanup SOP rather than swept.

Step 7 - Re-plug at 30 days and close on the number, not the impression. Re-plug every opening on the map, including the ones that never reopened, and re-count at the same 48 hour window. Acceptance: a second activity rate on the same denominator as the first, all method placements re-read, and either a documented close-out or a documented method change. Wrong looks like a close-out written on a walk-by where nothing was plugged, which makes the program unverifiable in hindsight. Stop rule: reopen rate at or above 50 percent of openings plugged at the 30 day recheck means the method is not reducing the population, so the method changes and the harborage list is re-walked rather than more bait being placed. Hazard: every trap set comes out at close-out and is counted back by number, because a snap trap left in ground cover is what a child or a dog finds next spring.

The record this produces

On the site sketch and ticket: numbered openings with zone, photograph and measured distance to the nearest structural element; the 811 ticket number and mark-walk date; plug date, plug material and recheck date; reopened count over plugged count at each recheck with both figures written; method assigned per opening with trap or station numbers; the signed harborage list with owners, dates and refusals; and the trap recovery count at close-out.

The activity rate is the column that matters, because it is the only figure that says whether the program worked, and it survives a change of technician. The office reads refused harborage items against callback history, since an account that has declined the same item twice is a renewal conversation.

Worked pass: single family with detached garage, four zones

Twenty-two openings mapped across four zones: 9 along the rear fence line, 6 behind the detached garage, 4 under the deck and 3 at the woodpile, totalling 22.

Step 2 fails at opening 14, measured 18 inches from the garage footing with the spoil fan running under the slab edge, against the 3 foot screen. The stop rule fires: photographed with its measurement, not plugged and not filled, referred to the service manager. That leaves 21 to plug, and 21 plus the 1 referred equals the 22 mapped.

The 811 ticket is filed and the marks walked. The customer identifies a private irrigation lateral crossing the rear fence line, which one-call does not locate, so the two trap anchors in that zone are hand-dug rather than driven.

Plugs go in with crumpled paper and site soil, and the recheck is set at 48 hours. Nine openings reopen: 5 on the fence line, 3 behind the garage and 1 at the woodpile, which is 9 of 21, or 43 percent. Six of the nine are accessible for traps; the other three sit in dense juniper where a trap cannot be tended safely, so tamper-resistant stations go in at those three per the bait station SOP.

The harborage list carries four items with owners: the woodpile onto a rack off the soil, the juniper cut back a foot from the foundation, the bird feeder moved off the lawn, and the pet food brought in at night. The customer signs three and declines the juniper, logged with the date.

At 30 days all 21 openings are re-plugged and re-read at 48 hours. Three reopen, all in the declined juniper zone, which is 3 of 21, or 14 percent, under the 50 percent gate, so the method holds. The six traps are recovered and counted back, the three stations stay on the route, and the juniper refusal goes into the close-out note as the reason the remaining activity sits where it does.

References

• Product label and EPA registration number for anything applied, legally binding and governing species, site and rate
• 811 one-call notification, with the notice period and private-line exclusion set by your state's underground damage prevention statute
• Aluminum phosphide and burrow cartridge labels, for restricted-use status, applicator certification and the buffer distance around occupied buildings on the current label
• See related: Rodent Bait Station Placement and Servicing; Rodent Exclusion and Trapping; Moisture and Conducive Condition Report