Holey rock

MonoMonday – Rock
Locally on some beaches there are several rocks riddled with dozens of holes and burrows.   I think this one is limestone and the holes have been caused by various sea creatures in the past. The smaller burrows were probably made by sea worms while the larger rounded holes would have been made by piddocks which are mollascs that can bore through rocks.  Their work can often be seen as tiny holes in shells where they have tried to consume the creature inside.


(Thanks to Nickimags888. for hosting today's challenge)