anchor.diff:  
       procedure Feed(Amount:single);
       procedure AbandonWalk;
  -    function GetDesiredPassability(aIgnoreRoads:boolean=false):TPassability;
  +    function GetDesiredPassability: TPassability;
       property GetOwner:TPlayerIndex read fOwner;
       property GetHome:TKMHouse read fHome;
       property GetUnitAction: TUnitAction read fCurrentAction;
  
positive.code: 
    //First make sure the animal isn't stuck (check passibility of our position)
    if (not fTerrain.CheckPassability(fCurrPosition,GetDesiredPassability))
    or fTerrain.CheckAnimalIsStuck(fCurrPosition,GetDesiredPassability,false) then begin
      KillUnit; //Animal is stuck so it dies
      exit;
    end;
  
negative.code: 
  
  //Specific unit desired passability may depend on several factors
  function TKMUnit.GetDesiredPassability: TPassability;
  begin
    Result := fResource.UnitDat[fUnitType].DesiredPassability;
  
  