The name "Sea Mouse"  does not mean that a little mouse scurries on the oceans floor.  It is actually a worm that spends most of its life on the ocean floor.  Its pointy "fur" can give a painful poisonous sting.  It is a good thing beachcombers and swimmers do not have to worry about getting stung!  The people who need to worry about this animal are the many fisherman who comb the ocean floor who put nets on the bottom in search of clams.