There are 76 species in 19 genera of this beetle family in North America.
The ridges along their elytra are hollow and are easily broken, releasing noxious fluids. They have joints along their legs that release foul fluids as well. These defense systems are very effective as other beetles and moths will mimic them.
The larvae prefer decaying wood, feeding on the fluids from fungal infestations. The adults are thought to feed on nectar and occasionally another insect.
Most species of this family have aposematic coloration. Often you can find these insects aggregating in large numbers.