Boring and bioclaustration cavities produced by animal behaviors are prevalent in reefs throughout geologic history, and they preserve erosive and symbiotic associates not typically found in the body-fossil record. A review of the major tracemaking clades demonstrates that bioerosive behaviors occur among disparate groups, having evolved repeatedly and independently. Factors that facilitate bioerosion among heterotrophs, especially increased nutrient supply and substrate exposure time, are expected to strengthen with modern climatic and anthropogenic impacts, and potentially accelerate destructive processes in the carbonate budget of reefs.