What are crawfish and how do you eat them?

Crawfish are considered a staple of cajun cuisine.  Many Louisiana natives and surrounding southern states eat these crustaceans.  To eat crawfish, sometimes called crawdads or mudbugs, you first need to purchase them.  Crawfish are usually sold by the sack with typical weights around 30-40 pounds.  You must then clean the crawfish as their natural habitats are within mud, swamps, and muck.   Rinsing them thoroughly in water is required.  Many will do this a sack at a time and continue to rinse until the water is crystal clear noting that they're clean.  Others go a step further through a process of purging.  This is using salt to have the crawfish clean out its insides.  Many think purging is a myth and simply skip this step.  Once clean, you'll want to bring a large pot (typically 80+ quarts in size) of water to a rolling boil.  Add in spices to flavor the water.  There are also pre-made bags of spice known as 'boil.'  Boil the crawfish until they float to the top and turn bright red.  Then allow the crawfish to soak to absorb the added spice.  This process can last as long as an hour or more, though 30 minutes is fairly typical.  Many people will add potatoes, corn, onions, and other sides to their boil.  Learning to peel a crawfish is an art, but can be quickly done by twisting off the tail.  Peel the rest of the shell off and eat the tail.  Many will also suck the head to get a burst of flavor.