MIHS Challenge 2 - solution

breed [predators predator]      ;; this statement declares a new breed of turtles called "predators"
breed [bugs bug]                ;; the first name refers to ALL bugs; the second name can refer to
                                ;; one specific bug (for example bug 7)

to setup
  clear-all
  set-default-shape bugs "bug"  ;; sets the default shape for ALL bugs
  set-default-shape predators "circle"
  create-bugs 10
  ask bugs 
  [
    setxy random-xcor random-ycor
  ]
  ask bug 7                     ;; asks one specific bug to make itself bigger
  [
    set size 2
  ]    
  ;; the predator breed contains one turtle that is used to represent
  ;; a predator of the bugs (a menacing circle)
  create-predators 1 
  [
    set shape "circle"
    set color white
    set size 1.5
    set heading 315
    setxy 0 0
  ]
  reset-ticks
end 

to go               ;; when the "go" button is clicked, this loop repeats until the button is clicked again
  move-bugs         ;; this calls the procedure named "move-bugs" defined below
  move-predator     ;; this calls the procedure named "move-predator"
  tick
end 

to move-bugs        ;; this makes the bugs move when it is "called" from the "to go" loop above
  ask bugs          ;; asks ALL bugs to move
  [
    fd .5           ;; forward 1 step
    rt random 10    ;; turn right
    lt random 10    ;; turn left
  ]
    ask bug 7 [fd 1]     ;; asks one specific bug to make an extra move
end  

to move-predator    ;; this makes the predators move
  ask predators
  [
    fd 1            ;; forward 1 step
    rt random 10    ;; turn right
    lt random 10    ;; turn left
  ]
end