private void scanBoard() {
		boardHasUneaten = boardHasUnseen = false;
		final int start = boardBuffer;
		final int end = boardBuffer + boardSize;
		for(int i=start; i<end; i++) { //scan within perimeter of walls and doors
			for(int j=start; j<end; j++) {
				
				int content = board[j][i];
				int distToX = j-meX, distToY = i-meY;
				int absDistToX = Math.abs(distToX), absDistToY = Math.abs(distToY);
				int absDistToXY = absDistToX + absDistToY;
				int x = meX+distToX;
				int y = meY+distToY;
				
				if (content == UNKNOWN) {
					boardHasUnseen = true;
				}
				else if (content == FOOD) {
					boardHasUneaten = true;
				}
				if (content == UNKNOWN || content == FOOD) {
					//if it's closer then the last one we saw
					if (absDistToXY < distToDest) { 
						distToDest  = absDistToXY;
						distToDestX = absDistToX;
						distToDestY = absDistToY;
						destX       = x;
						destY       = y;
						if (DEBUG) { System.out.println("UNKNOWN || FOOD destX:"+destX+" destY:"+destY); }
					}
				}
			}
		}
		
		//include the four possible door locations as unknowns
		findClosestDoor(UNKNOWN);
	}