Which of the following structural deficiencies can invite pest entry?

Gaps at the base of doors, even as small as 1mm, can provide an entry point for pests. Many wood-destroying insects and other pests can exploit surprisingly small openings to access the interior of a structure. For instance, termites, ants, and even rodents can find their way through these minor gaps, potentially leading to infestations that can cause significant structural damage over time.

While cracked windows without screens and unsealed vents can also serve as entry points, they may not be as immediately effective as the gaps at door bases. Closed shutters during daylight do not provide a means of entry; rather, they might offer protection or concealment for pests already inside. Thus, the first option highlights a more direct and common structural deficiency that can compromise a building’s pest resistance.