Small pieces are important for thread.
I have to tell you that I have a long haired cat and he was just groomed. I saved all his fur. I also comb and save fur all winter. Now when it gets a little warmer I will put a handful of his fur outside for the birds. Sometimes into a suet wire cage. No joke the birds wait in line! As I watch the chickadees gather the fur, before they fly away they look like they have a little beard. Those baby birds must be warm and comfortable.