/** Whenever actors contains more foes than friends, this OpossumCritter plays dead.
   *  Postcondition: (1) The state of all actors in the grid other than this critter and the
   *  elements of actors is unchanged. (2) The location of this critter is unchanged.
   *  @param actors a group of actors to be processed
   */
  public void processActors(ArrayList<Actor> actors)
  {
    int friends = 0, foes = 0;

    for (Actor a : actors)
    {
      if (isFriend(a))
        friends++;
      else if (isFoe(a))
        foes++;
    } 1

    if (foes > friends)
    {
      numStepsDead++;
      setColor(Color.BLACK);
    }
    else
    {
      numStepsDead = 0;
      setColor(Color.ORANGE);
    }
  }

1. Or use one counter: add 1 for a friend, subtract 1 for a foe.

  /** Selects the location for the next move.
   *  Postcondition: (1) The returned location is an element of locs, this critter's current location,
   *  or null. (2) The state of all actors is unchanged.
   *  @param locs the possible locations for the next move
   *  @return the location that was selected for the next move, or null to indicate
   *          that this OpossumCritter should be removed from the grid.
   */
  public Location selectMoveLocation(ArrayList<Location> locs)
  {
    if (numStepsDead == 3)
      return null;
    else if (numStepsDead > 0)
      return getLocation();
    else
      return super.selectMoveLocation(locs);
  }