Some Words from the Professionals
By Carol Brorsen, Fri., Jan. 21, 2000
The best way to discourage rats in your home is to limit food sources outside and to make access to the indoors impossible to them.
Any opening into the house larger than a nickel should be sealed. All cracks, openings where pipes enter buildings, and places where the roof intersects, are potential rat entry points.
Using plastic, wood, old T-shirts, or duct tape to plug holes is usually a waste of time. Use rat-proof material such as 26-gauge or thicker galvanized sheet metal, galvanized wire, hardware cloth, or cement mortar to seal the building.
Seeing active rats during the day generally indicates a high population of rats in the area.
If you hear gnawing, clawing, climbing in walls and ceilings, squeaks, and fighting noises, you may have rats.
If your cat or dog excitedly probes an area of floor or wall, you may have rats.
If you have rats, trapping is recommended. As one pest control manual from 1974 explained, "Trapping has several advantages: 1) it does not rely on inherently hazardous rodenticides; 2) it permits the user to view his successes; and 3) it eliminates rat deaths in inaccessible locations, which frequently create odor problems when poisoning is done within dwellings."
Rats are very suspicious of new things. Try putting unset, baited traps out for a few days. This allows the rats to become accustomed to the trap and the rat trapper to experiment with which kind of bait works best.
Peanut butter, cracked pecans, dried fruit, or dried vanilla pudding mix make good bait.
Because rats are extremely nearsighted, they use their whiskers and fur as sensors. Rats travel along walls and avoid open spaces as much as possible. Traps should be set so that the trigger is against the wall, or in the direct path of the rat. Traps may also be secured with wire to rafters or overhead pipes -- a common area for roof rats to scurry.
If you have toilets or sinks that haven't been recently used, the water in the traps can evaporate or settle and rats may enter the house through the sewer pipes. Flush the commodes and run water through the sink about once a week to discourage rat invaders. Sources: Jeff Hill, Bug Master; Louis Gonzales, supervisor for T.V. inspection of Austin Wastewater System; David Grand, Applied Pest Control; Ron Dotson, supervisor of Austin's rodent and vector control.