Associate Certified Entomologist (ACE) Practice Exam

What is a common measure used to prevent rodents from entering a structure?

1. Layering mulch

2. Screening windows

3. Planting deterrent plants

4. Sealing entry points

The correct answer is: Sealing entry points

Sealing entry points is a widely recognized and effective method for preventing rodents from entering a structure. Rodents can exploit even the smallest openings—such as gaps around pipes, vents, and doorways—to gain access to indoor environments. By identifying and sealing these entry points with materials like caulk, steel wool, or hardware cloth, the likelihood of rodent infiltration is significantly reduced. In contrast, while layering mulch, screening windows, and planting deterrent plants each have their specific benefits in pest management, they do not directly address the primary behavior of rodents seeking shelter and nesting sites inside structures. Layering mulch can actually provide an environment that harbors rodents if it is too thick or left unmaintained. Screening windows may help with other pests but does not prevent rodents from entering through other means. Planting deterrent plants can be useful for some wildlife but is not a foolproof method for keeping out rodents, as they often look for shelter in buildings rather than relying solely on outdoor vegetation for deterrence. Thus, sealing entry points remains the most comprehensive preventive strategy for rodent control.