Ants, cockroaches and flies are the three most commonly reported insect pests in Massachusetts homes, and depending on the species, these pests can be problematic all year round in the state. German and brown-banded cockroaches both spend their entire lives hiding inside human structures where they forage and breed. Ants are not generally an issue indoors during the colder months in the northeast but carpenter ants can maintain nests within a home’s structural wood throughout the winter season. Like many true bugs, such as boxelder bugs and brown marmorated stink bugs, cluster flies gravitate into homes during the fall season to seek refuge from the coming winter cold. Cluster flies tend to congregate in attics, while other Diptera fly species begin slowing their movements once temperatures drop. Another group of flies from the Diptera order that are more commonly known as a gnats, can become more abundant indoors during the winter season due to overwatering indoor plants. These gnats are commonly referred to as fungus gnats, and although they do not bite or spread disease, they can become a serious nuisance in homes throughout the year.

Everyone is familiar with the tiny mosquito-like bugs known as gnats, which tend to fly erratically around garbage dumpsters and other sources of filth. Fungus gnats look similar to all other types of gnats, as they are usually only a couple of millimeters in body length, but fungus gnats can be distinguished by their habit of flying into people’s faces where they sometimes enter nostrils, ears and mouth. Fungus gnat larvae develop in soil, making them common garden pests, but larvae also develop in soil located within indoor potted plants. Fungus gnat larvae are abundant in soil, and many indoor infestations start when infested commercial potting soil is purchased from retailers. In some cases, fungus gnats can be found congregating in indoor drains where they feed on decaying organic matter. Since fungus gnat larvae thrive in moist soil, overwatering indoor potted plants during the winter can cause adults to emerge and swarm indoors. During the winter, indoor potted plants require half the amount of water than they do during the summer, so overwatering indoor plants is not uncommon during the winter season. Reducing indoor plant watering or placing infested potted plants outdoors will usually end infestations.

Have you ever found gnats in your home during the winter months?