Ground beetle (likely a bombardier beetle)

Found under stones, leaf litter, logs, and other sheltered, damp ground habitats; often wanders indoors accidentally.

Predatory, feeding mainly on small insects, larvae, and other arthropods; adults may also scavenge.

Mostly nocturnal and fast-moving, hiding by day. Bombardier beetles can eject a hot, irritating chemical spray when threatened; they undergo complete metamorphosis.

Not dangerous to people, though the defensive spray can irritate skin or eyes. Beneficial as a predator of other insects and generally harmless indoors.