// Update is called once per frame
    void Update()
    {
        // Increase harvest timer.
        _harvestTimer += Time.deltaTime;

        // Return to base if resource source depleted or inventory is full.
        if (!_currentSource || _inventory.IsFull())
        {
            _pheromonePlacement.SetPheromoneType(EPheromoneTypes.Food);
            _states.currentState = EAntStates.ReturnToBase;
            return;
        }

        // Harvest some resources if possible (timer).
        if (_harvestTimer >= _harvestSpeed)
        {
            _navHelper.Stop();

            _currentSource.DecrementCapacity();
            _inventory.IncrementCapacity();
            _harvestTimer = 0.0f;
        }
    }