Hermit crabs are animals.
A jack staff -LRB- also spelled as jackstaff -RRB- is a small vertical spar -LRB- pole -RRB- on the bow of a ship or smaller vessel on which a particular type of flag , known as a jack , is flown .. flag. flag. jack. Jack ( flag ). The jack staff was introduced in the 18th century .. jack. Jack ( flag ). The jack is typically flown from military vessels , including submarines , while at anchor or moored pierside , but not while underway .. jack. Jack ( flag ). Civilian vessels such as private yachts have also been known to fly the jack of the nation of their homeport , also from a jackstaff , while moored or at anchor .. jack. Jack ( flag )