/// <summary>
/// Unregisters the creature from it's niche.
/// </summary>
internal void UnregisterNiche()
{
_niche = null;
}
/// <summary>
/// Registers the creature to the given niche.
/// </summary>
/// <param name="niche">The niche.</param>
internal void RegisterNiche(Niche niche)
{
_niche = niche;
}