Shellfish have several ocean predators, but what you are most likely seeing are holes created by the beaks of sea gulls.
Drills are for making accurate holes in material
and hand drill drills holes into woods
For cutting round holes.
It drills holes into the ground.
and hand drill drills holes into woods
the hammer function on drills is used with a masonary bit and used to drill holes in brick or concrete block.
it is used for drilling holes in materials such as metal.
To drill holes in bone or wood.
Oyster drills
Diamond tipped drill bits
A huge auger that drills holes in the ground to a great depth,
Tools for making holes or for starting a fire.