Mold Feeding Insects: Does Mold Attract Insects?

When homeowners discover mold in their home, or moisture (both active moisture or moisture retention from a previous leak), there is often a question of whether or not there are insects associated with the mold growth i.e. does the visible mold attract insects, which, in turn, feed off the mold? In short, the answer is yes; mold growth and moisture can attract certain particular insects, which can create a fleeting insect infestation in your property.

One reason is that certain types of insects, such as the ‘foreign grain beetle’ or ‘Ahasverus advena”, feed predominantly on microbial fungi (mold/mildew). Furthermore, these types of insects require similar environments as mold to thrive, such as high humidity; generally, mold can begin to grow when the relative humidity levels are greater than 55-60% in a property, which is why homeowners often see mold growth in attics. The Foreign Grain Beetle can often be found in older homes where bathrooms have higher humidity levels which permit mold growth and ideal habitats for the insect.

Another insect, known as ‘booklice’, are miniscule insects which also found in high humidity areas with mold growth. They are commonly found in structures with higher moisture levels, as well as poorly ventilated structures. These types of insects are most discovered in household items, such as books and rugs. Indicators: One indicator of insect infestation or presence in a property is the fecal pellets left behind in a damp area i.e. such as on a damp drywall in a basement. Homeowners can occasionally mistaken the fecal pellets for mold, but the two are correlated, so it isn’t completely unreasonable to make the association. What can then occur for homeowners is not only being subjected to the potential mycotoxins from mold growth, but also mite allergens.

​Finally, spiders can also be a potential indicator for mold growth since spiders are predators on other live insects. Therefore, if there are several spiders congregating in one area of the home, there may be other live insects in that area, as well as fungi growth at the very bottom of that food chain. In conclusion, mold does attract insects, but it varies dependent on the conditions in the property and is not a foregone conclusion.