You will eventually come across the nest. Take the first fog door on the left and bear left.
You can find them in Things Betwixt. From the bonfire outside the Old Firekeepers house, head towards Majula.
As such, it is advised to trade a maximum of ten items at a time.
You! You! Give us Smooth! Yes! You! Give us Silky!" Dyna and Tillo are an NPCs in Dark Souls 2.