Each opening in a wall, the ceiling or the roof needs a filter or screen that stops animals, invertebrates included, getting in or out. The filter or screen material must be strong enough mechanically to take whatever airflow load it faces, stay intact under routine cleaning, and resist corrosion and being penetrated by animals or invertebrates.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.