Which of the following is NOT typically a sign of mold infestation?

In the context of identifying mold infestations, the key characteristic that distinguishes signs of mold presence from those of healthy environments is the condition of the surfaces being evaluated. Visible growth of mold, constant odors indicating mold presence, and water stains on surfaces are all direct indicators of a potential mold problem.

Dry, clean surfaces, however, are typically indicative of a lack of mold. Mold thrives in damp, humid conditions, and its growth is often accompanied by moisture or water issues. Therefore, finding surfaces that are dry and clean would suggest that mold is unlikely to be present, making this the correct choice in identifying what is NOT a sign of mold infestation. This understanding is crucial for anyone dealing with real estate, as it reinforces the importance of inspecting for moisture and odor issues rather than merely assessing visible surface conditions.