Once a burrow is verified, the applicator picks the method the law and the site allow. This page is the honest menu — including the ideas that sound good and aren't legal here.
| Method | Legal in CA? | Works? | When we use it |
|---|---|---|---|
| Carbon-monoxide burrow injection EPA-registered device (e.g. pressurized exhaust rodent controllers) pumps CO into the tunnel; rats pass out in the nest. | Yes — licensed applicator, registered device, label buffer from occupied structures | High. Spreads through the whole tunnel regardless of soil moisture. | Open ground: lots, fence lines, landscape beds, creek banks — never within the label distance of a building, basement or garage. All secondary holes plugged first. |
| Rat-sized smart traps Electronic or snap traps inside a tunnel baffle sized for a rat body (2–3 in). Cameras/sensors log each catch. | Yes | High on runways; needs placement from the map. | Everywhere, especially near structures where gas is off the table. Cat- and owl-safe by geometry. Synthetic lures beat trap shyness. |
| Exclusion Sealing entry points, hardware cloth, door sweeps, pallet spacing, dumpster pads. | Yes | The only thing that lasts. | Every site, as a contract deliverable. Sealed entries are a metric cities pay for. |
| Contraceptive bait EPA-registered liquid rat contraceptive in tamper-proof stations. | Yes | Slows rebound between treatments. | Hold phase on large sites; non-toxic to cats and owls. |
| Working cats Sterilized, vaccinated colony cats living on the site, tracked on the mesh. | Yes | Suppression, not eradication. Their GPS shows where the rats are. | Hold phase. See the cat program. |
| Ratting terriers with a handler | Yes | Very effective on small sites; labour-heavy. | Barns, yards, one-off clean-outs where a handler can supervise. |
| Flooding burrows with water | Yes on private land — but you own any erosion, foundation or runoff damage | Low–moderate. Tunnels have dry chambers and escape exits. | Rarely; only in open soil far from foundations, sidewalks and storm drains, with traps set at the exits. |
| Gas / smoke cartridges | Yes outdoors, per label | Moderate in open soil. | Rarely — fire risk in mulch, dry roots and ivy; CO devices do the same job cleaner. |
| Ferrets sent into burrows | No — ferrets are illegal to own in California | — | Never. Terriers are the legal equivalent. |
| Improvised vehicle-exhaust hoses | No for commercial work — not a registered device, unsafe for the operator | — | Never. |
| Second-generation anticoagulant poison | Restricted statewide in California; secondary poisoning of owls, hawks, cats | — | Never. It's also the thing our working cats would eat. |
| Drones firing BBs / pellets | No — federal ban on weaponized civilian drones; city ban on discharge | — | Never. |
CO travels through soil into basements and slab cracks. We follow the device label's buffer from any occupied structure with no exceptions, and we never gas inside a building.
Fumigant devices and any paid pest work are done by a Qualified Applicator registered with the County Agricultural Commissioner, or a licensed structural operator for work in and under buildings. Mapping and monitoring staff don't apply anything.
Baffled traps, no toxic bait, and owl checks mean the site's cats, dogs, owls and hawks are never the ones that get hurt.
Photos, GPS, method, applicator, date — per burrow. If a health inspector asks, the answer is a PDF, not a memory.