C#

public void run()
{
    foreach (IActor actor in actorsOnField)
    {
        Thread thread = new Thread(delegate() { move(actor); });
        thread.Start();
    }
}

public void move(IActor actor)
{
    while (true)
    {
        int rand = RandomNumber.GetRandomNumber(1000, 2000);
        Thread.Sleep(rand);

        if (!isPaused)
        {
            lock (_grid)
            {
                actor.move(this);
            }
        }
    }
}

/// <summary>
/// This is the main method called from the Field class from a thread.
/// This is the only method called. All movement logic should be contained here.
/// </summary>
/// <param name="field">The playing field passed into this object from the thread</param>
public void move(Field field)
{
    IActor[,] grid = field.Grid;

    //if (grid[CurrentLocation.Y, CurrentLocation.X] == null)
       // return null;

    Location moveTo = MoveToRandomLocation(field);
    if (moveTo != null)
    {
        grid[CurrentLocation.Y, CurrentLocation.X] = null;

        CurrentLocation.X = moveTo.X;
        CurrentLocation.Y = moveTo.Y;

        grid[CurrentLocation.Y, CurrentLocation.X] = this;
    }

    reproduce(field);
}

public Herbivore reproduce(Field field)
{
    //percentage chance to reproduce.
    int chanceToReproduce = 10;

    //list containg all adjacent actors
    List<IActor> neighbours = GetAdjacentActors(field);

    //TODO -> only include actors that are of this calss type.
    chanceToReproduce = neighbours.Count * chanceToReproduce;

    //random number to calculate against the chance to breed
    int rand = RandomNumber.GetRandomNumber(0, 100);

    //get the empty locations to spawn a new herbivore
    List<Location> adjacentLocations = this.GetAdjacentLocations(field);

    //store the empty locations adjacent to this actor
    List<Location> emptyLocations = new List<Location>();

    foreach(Location loc in adjacentLocations)
    {
        if (field.Grid[loc.Y, loc.X] == null)
            emptyLocations.Add(loc);
    }


    //if(chanceToReproduce >= rand)
    if (chanceToReproduce >= rand && emptyLocations.Count > 0)
    {
        Herbivore herb = new Herbivore(emptyLocations[0].X, emptyLocations[0].Y);
        field.ActorsOnField.Add(herb);
        field.Grid[emptyLocations[0].Y, emptyLocations[0].X] = herb;
        return herb;
    }

    return null;
}