turtles eat grasses

turtles-own [energy]

to setup 
      clear-all
      setup-patches
      setup-turtles
      do-plots
      reset-ticks
end 

to setup-patches
     ask patches [ set pcolor green ] 
end 

to setup-turtles
      create-turtles number
      ask turtles [
          setxy random-xcor random-ycor
      ]
end 

to go
      if ticks >= 500 [ stop ]
      move-turtles
      eat-grass
      reproduce
      check-death
      regrow-grass
      tick
      do-plots
end         

to move-turtles
     ask turtles[
               right random 360
               forward 1
               set energy energy - 1
              ]
end 

to eat-grass
      ask turtles [
      if pcolor = green [
              set pcolor black
              set energy (energy + energy-from-grass)
              ]
              ifelse show-energy?
                  [ set label energy ]
                  [ set label "" ]
      ]
end 

to reproduce 
      ask turtles [
             if energy > birth-energy [
                          set energy energy - birth-energy
                          hatch 1 [ 
                            set energy birth-energy
                            ]
             ]          
      ]
end 

to check-death
     ask turtles [
     if energy <= 0 [ die ]
     ]
end 

to regrow-grass
     ask patches [
     if random 100 < 3 [ set pcolor green ]
     ]
end 

to do-plots
     set-current-plot "Totals"
     set-current-plot-pen "turtles"
     plot count turtles
     set-current-plot-pen "grass"
     plot count patches with [pcolor = green]
end