NWCO - Nuisance Wildlife Control Operator Exclusion and Habitat Modification 2 — Questions and Answers
Question 1: What is the minimum recommended gauge of hardware cloth for excluding raccoons?
- 19-gauge (window screen weight)
- 16-gauge
- 14-gauge or heavier (Correct answer)
- Any plastic mesh
Correct answer: 14-gauge or heavier
14-gauge or heavier is required because raccoons have sufficient strength to tear lighter materials.
Raccoons can tear through 16-gauge and lighter hardware cloth. Professional exclusion requires 14-gauge or heavier galvanized hardware cloth with 1/2-inch mesh, secured with screws and washers (not staples). Window screen and plastic mesh are inadequate. For high-pressure areas, 12-gauge or sheet metal may be needed.
Question 2: How far should the horizontal footer of an L-shaped buried mesh barrier extend outward?
- 6 inches
- 12 inches
- 24 inches or more (Correct answer)
- 48 inches
Correct answer: 24 inches or more
A minimum 24-inch horizontal footer prevents burrowing animals from digging underneath the barrier.
When burrowing animals encounter the vertical barrier, they dig downward along it. The horizontal footer extending at least 24 inches creates a floor they cannot dig past. The mesh should be buried 4-6 inches deep with 14-gauge galvanized hardware cloth. A 12-inch footer may be insufficient for determined diggers like groundhogs.
Question 3: What type of one-way exclusion device is MOST appropriate for squirrels exiting a soffit opening?
- A spring-loaded door
- A cone or funnel-shaped device with wire mesh tube (Correct answer)
- A rubber flap covering
- An ultrasonic sound emitter
Correct answer: A cone or funnel-shaped device with wire mesh tube
A cone/funnel device allows squirrels to push through and exit but prevents re-entry due to the narrowing funnel shape.
Wire mesh cone or funnel devices have the wide end attached to the building and narrow end extending outward. Squirrels push through the narrow opening to exit but cannot re-enter. Spring-loaded doors can malfunction or injure animals. Rubber flaps may allow re-entry. Ultrasonic devices have limited effectiveness.
Question 4: Which habitat modification is MOST effective at reducing bird feeding opportunities that attract nuisance wildlife?
- Installing more feeders farther from the house
- Removing bird feeders or using wildlife-resistant designs with seed catch trays (Correct answer)
- Switching to cheaper birdseed
- Moving feeders to the front yard
Correct answer: Removing bird feeders or using wildlife-resistant designs with seed catch trays
Removing feeders or upgrading to wildlife-resistant designs eliminates the food subsidy attracting nuisance species.
Bird feeders attract rodents (which attract snakes and predators), raccoons, squirrels, and bears. Complete removal during problem periods is most effective. Wildlife-resistant designs with seed catch trays can reduce but not eliminate attraction. In bear country, feeders should be removed entirely April through November.
Question 5: What is the correct height for a chimney cap to prevent wildlife entry while maintaining proper draft?
- Flush with the chimney top
- At least 5 inches above the flue tile with appropriate mesh screening (Correct answer)
- 12 inches above the roofline
- Height doesn't matter as long as mesh covers the opening
Correct answer: At least 5 inches above the flue tile with appropriate mesh screening
Chimney caps should extend at least 5 inches above the flue tile with appropriate mesh to exclude wildlife while maintaining draft.
Professional chimney caps should extend at least 5 inches above the flue tile. Mesh screening should be stainless steel or galvanized with 5/8-inch openings. A flush cap restricts draft. Too fine a mesh restricts airflow and accelerates creosote buildup. Caps should be secured with masonry screws or clamp systems.
Question 6: When should tree branches be trimmed as part of wildlife exclusion?
- Only during winter
- Branches within 6-8 feet of the roof should be trimmed to eliminate wildlife bridge access (Correct answer)
- Tree trimming is never part of wildlife management
- Only branches touching the roof
Correct answer: Branches within 6-8 feet of the roof should be trimmed to eliminate wildlife bridge access
Branches within 6-8 feet provide jumping or climbing access for squirrels and raccoons.
Gray squirrels can jump horizontally 8-10 feet. Raccoons use overhanging branches as direct access routes. Professional recommendations include maintaining at least 6-8 feet of clearance from the roofline, gutters, and walls. Only trimming touching branches is insufficient as squirrels bridge 5-6 foot gaps easily.
NWCO - Nuisance Wildlife Control Operator Exclusion and Habitat Modification 2
What is the minimum recommended gauge of hardware cloth for excluding raccoons?