I love to eat crustaceans.  How about you? 

Background:

Look at preserved specimens of hermit crabs, fiddler crabs, ghost crabs, stone crabs, shrimp, and lobsters during this part of the unit to discover the characteristics of crustaceans.  Crustaceans are invertebrates characterized by an external skeleton and jointed appendages.  They breathe through gills, and molt or shed their exoskeletons as they grow.  Point out that horseshoe crabs are not crustaceans and are in the same class as spiders and scorpions.  The odd ball of this group is the barnacle, think of him as a crab stuck to a rock by his head and waving his feet in the air to catch food.

Read the book Pagoo by Holling to learn about the life of a hermit crab.  This book is packed with information about different types of sea life.  It introduces the life of the hermit crab as zooplankton and traces its adventures to adulthood. 

Bring in land hermit crabs during this part of the unit have hermit crab races.

Make a diagram of a blue crab which includes the back and front views.  Duplicate it on colored construction paper and have the students cut it out, stuff it with three cotton balls and staple it together. Get the rolling eyes from the craft store and glue them on top.