Eagle

  Write a class called Eagle that extends the Critter
   class.  The instances of the Eagle class switch back and forth between red
   and blue in an increasing pattern.  They should be red for one move and then
   blue for one move.  Then they should be red for two moves and then blue for
   two moves.  Then they should be red for three moves and then blue for three
   moves.  Then they should be red for four moves and then blue for four moves.
   And so on, each time increasing the number of moves at a particular color by
   one.  They should be displayed using a less-than character followed by a
   greater-than character ().  They should always hop whenever possible.  If
   they can't hop, they should turn right if there is a wall in front of them
   and otherwise they should infect.