On a recent trip to Pennsylvania I found this broad-headed bug (family Alydidae) outside my hotel at dusk. These insects overwinter as adults, and this one may have been trying to gain entry into the hotel for the winter. During warmer months they use their piercing/sucking mouthparts to feed on plants and seeds, although most aren’t notable crop pests.
Like their fellow true bugs in the stinkbug family (Pentatomidae), these insects are known to emit foul odors from scent glands. Their odor is similar to bad breath and serves to deter predators.
A number of broad-headed bugs also exhibit mimicry to avoid predation. Many young nymphs (and some adults) mimic ants to blend in with local ant populations. Adults tend to more closely resemble wasps, and some may possess brightly-colored abdomens. They can open their wings to display this coloration as a warning to predators of their noxious scent.