Several species of fish use tools to hunt and crack open shellfish, extract food that is out of reach, or clear an area for nesting. Among cephalopods (and perhaps uniquely or to an extent unobserved among invertebrates), octopuses are known to use tools relatively frequently, such as gathering coconut shells to create a shelter or using rocks to create barriers.
Several species of fish use tools to hunt and crack open shellfish, extract food that is out of r:each, or clear an area for nesting. Among cephalopods (and perhaps uniquely or to an extent unobserved among invertebrates), octopuses are known to use tools relatively frequently, such as gathering coconut shells to create a shelter or using rocks to create barriers.