The Dog Whelk is a sea snail with a tough, spiral shell that you can find clinging to rocks in rockpools. It’s a predator that feeds mainly on mussels and barnacles by using a sharp, drill-like tongue to bore holes into their shells and eat what’s inside. Dog whelks help control the populations of these shellfish, which keeps the rockpool ecosystem balanced. They’re not harmful to humans and play an important role as natural “clean-up” hunters. Because they can survive in rough conditions, they’re often a good sign of a healthy, thriving rockpool.