Adult stink bugs are a common nuisance for homeowners, characterized by their distinctive, broad shape and their notorious defense mechanism—a pungent, unpleasant odor. These insects frequently become household pests, and their ability to move throughout a home is a primary concern for managing an indoor infestation. Understanding how these pests move is the first step toward effective mitigation.
The Truth About Stink Bug Flight
Adult stink bugs are fully capable of flight, possessing two pairs of wings that enable them to travel significant distances. The hardened outer forewings serve as a protective cover for the delicate, membranous hindwings used for propulsion. While they can fly, their movements in the air are often described as clumsy and ungraceful compared to other flying insects.
Their flight is frequently accompanied by a noticeable, audible buzzing sound created by the rapid vibration of their wings. This heavy, noisy flight pattern results from their somewhat bulky bodies and shield-shaped structure, making them prone to bumping into walls and other objects when indoors. Stink bugs primarily fly when actively seeking resources like new food sources, mates, or a suitable place to shelter for the winter.
Flight is an effective method for them to cover ground when walking is too slow, often employed when migrating to overwintering sites. They use their flying ability to move from agricultural fields to residential areas in the late summer and fall. Their movement is deliberate, not random, as they navigate toward favorable conditions like the warm, vertical surfaces of homes.
Identifying the Common Invader and Seasonal Habits
The most frequent home invader in the United States is the Brown Marmorated Stink Bug (BMSB), an invasive species first identified in the mid-1990s. This insect is recognized by its characteristic shield shape and mottled grayish-brown coloration. Adult BMSBs are approximately 17 millimeters long, nearly as wide as they are long.
A distinguishing feature of the BMSB is the alternating light bands on the antennae, along with darker bands on the thin outer edge of the abdomen. Throughout the summer, these bugs are predominantly found outdoors, feeding on a wide variety of plants, fruits, vegetables, and ornamental trees. This feeding behavior is concentrated in agricultural or garden settings.
As temperatures drop in the late summer and early fall, adults look for protected locations to enter a state of dormancy called diapause. They are attracted to the sunny, vertical surfaces of homes, where they congregate in large numbers before crawling into cracks and crevices. This overwintering behavior is why they are often discovered inside homes near windows, doors, and light fixtures when the weather cools.
They do not reproduce or feed while inside a structure, but they emerge from hiding spots on warmer winter days, becoming most noticeable indoors. This seasonal migration transforms them from an outdoor agricultural pest into an indoor nuisance pest.
Understanding the Odor and Practical Removal
The primary concern about these insects is the release of a foul-smelling chemical defense mechanism when disturbed or crushed. This pungent odor is produced by glands located on the underside of the thorax and the dorsal surface of the abdomen. The smell is composed of aldehyde compounds, specifically trans-2-octenal and trans-2-decenal.
These chemical secretions serve as a deterrent to predators, but they are also released when the bug is accidentally squashed, captured, or roughly handled. Once released, the odor can linger in the air and on surfaces for a noticeable period, making direct physical contact an undesirable removal method. The odor can even permeate the bag or canister of a vacuum cleaner if too many bugs are collected at once.
To remove them without activating their defensive odor, a gentle approach is recommended. One effective method is to use a simple trap: a dish of water mixed with a few drops of dish soap. The soap breaks the water’s surface tension, causing the bugs to sink and drown, which prevents the release of the smell.
Another practical solution is to use a shop vacuum or a dedicated vacuum with a disposable bag, which can be sealed and immediately discarded outdoors. Sealing exterior entry points, such as cracks around window frames, utility pipes, and siding, is the most effective way to prevent them from entering the home.