Why does the species matter for the control?
UC IPM says knowing whether a roof rat or a Norway rat is present determines the control. The two rats differ in how they move and where they live, so the placement of devices and the sealing points change with the species.
A roof rat is comfortable high in a building, using the roof line, the eaves, the trees and the overhead wires as routes. A Norway rat favours the ground, burrows and the lower parts of the building, and it is more often found under a deck, a shed or a slab edge. A device placed for one can miss the other entirely.
The UC IPM guidance is therefore the basis for the identification step. The technician looks at the droppings, the runs and the entries and records which species the signs point to. Where the evidence does not decide between them, the report says so, and the plan is written to cover both until the species is clearer.
How are the runs traced on a Fremont lot?
Runs are traced from the outside edges of the lot inward: the fence lines, the shrubs, the drains and the sheds. A run that stops at a wall marks the entry, and the entry is examined from both sides.
A fence line is a common rat road, and the grease marks along the boards show the path clearly. The technician follows the fence to the place it meets the house, a shed or a drain, and notes the distance from each point to the building.
The house end of the run is checked in the garage, the crawl space and the wall voids. A run that enters the garage through a gap under the door is a different job from one that enters a wall at the eave, and the report records which it is.
Where do the devices belong?
Devices belong on the runs, set against the wall where the animal walks, and in the spots where the signs are strongest. A device off the run is not likely to catch anything.
A snap trap is set square to the wall with its trigger where the animal’s body crosses. The technician checks the run for width and for any object that would stop the trap from firing. A trap set in the open floor of a garage, away from the wall, rarely catches a rat that is using the edge.
Bait stations are used where a pet or a child could reach an open device. The stations are sealed, placed on the run and checked on the schedule. The station number, its position and the date of each check are written in the report.
How is the entry sealed so that it stays sealed?
Metal mesh or a sheet-metal plate is fixed over the entry and sealed at its edges. Foam by itself is gnawed through, so it is used only to fill the space behind the plate.
A plate that is screwed into sound wood holds. A plate screwed into rotten wood fails at the screw, and the technician replaces the wood or uses a different fixing. Mesh pushed into a gap without a fixing is chewed around, so the mesh is fixed on at least two sides.
The sealed point is checked by eye at the next visit and by a light test where the gap is at the back of a cabinet or a machine. A point that has been reopened is recorded, because it shows the route is still in use.
What should a homeowner do while the plan runs?
Keep food in sealed containers, keep pet food indoors and in a closed bin, and clear the clutter along the garage walls. Leave the devices alone unless the technician has asked to move one.
A bag of pet food in a garage, a bird feeder under a window and a pile of cardboard against a wall all give rats a reason to stay close. Those are the changes that help the devices work, and the technician lists them in the report.
Moving a device or setting a new one without advice can take a trap off the run or put a device where a pet can reach it. A homeowner who wants a change should call the technician first.
