Misanthrope Housing Problem

to setup
  clear-all
  set-default-shape turtles "house"
  let i 1
  if Grid = true [set i HousesInRow]
  set-patch-size (700 / HousesInRow) 
  resize-world 0 (HousesInRow - 1) 0 i 
  ;; make green atoms on left
  ask patches with [pycor < i ]
    [ sprout 1 [ set color gray ] ]
  reset-ticks
end 

to go
  ;; asks to fill empty houses
  ;; move into the vacancy
let i true
  while [ i = true ] [ tick
      let Misanthrope one-of turtles with [color = grey]
          ifelse Misanthrope = nobody [set i false ]
          [ask Misanthrope [ set color green 
                            ask patch-here [ask turtles-on neighbors
                                                [set color red]]]]] 
end