This seems to be an early autumn convention of Boxelder bugs. They’ve congregated at the bottom of a tree.

When it begins to cool down in Wisconsin, these bugs may form large aggregations while sunning themselves in areas near their host plant – usually maple or ash trees. I’ve also seen them gather in other odd places…the corner of a building, around a door way, etc.

They are harmless to humans but considered nuisance pests. When the temperatures begin to cool in the fall, they sometimes invade houses and other man-made structures seeking warmth or a place to overwinter.

People often mistaken them with insects known as Stink Bugs – a different species.  However, boxelder bugs will release a pungent and bad-tasting compound upon being disturbed to discourage predation; this allows them to form conspicuous gatherings without being preyed on.

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