Boxelder bug

Common on boxelder and maple trees, especially near buildings; often gathers on sunny exterior walls and enters homes to overwinter.

Pierces plant tissues and feeds mainly on seeds and sap of boxelder, maple, and ash trees.

Adults aggregate in large groups in autumn and overwinter in sheltered places. They are strong fliers and may release a defensive odor when disturbed.

Harmless to people and pets; it does not bite or cause significant structural damage, though indoor aggregations can be a nuisance.