The process by which animals erode hard hard surfaces such as rocks and coral reefs, through drilling, grazing and burrowing. Bioerosion from organisms and animals who remove hard substrates is slower compared to erosion from storms or floods. However, over time the effects of bioerosion can be extraordinary. For instance, there is a theory that The English Channel is a result of bioerosion. Geologists and paleontologists are particularly interested in patterns of bioerosion because it can tell us a great deal about prehistoric sea levels, climatic conditions, and community evolution. Bioerosion traces in ancient limestones of the Bahamas, for example, have given us a direct indication of a rapid global sea level change about 125,000 years ago.