My co-op has discussed that there appears to be very little to do with the feathers (both colorful feather and down feathers), from the time you get access to the duck feeder relatively early in the game. They don't sell for very much money, so it seems pointless to feed the ducks regularly if the feathers don't have much value to produce. The earliest thing we can come up with is the colored feathers can be used for hats (only at level 50) and the pink boots... maybe down feathers for the down feather factory (level 74). All higher level factories. Can you incorporate one lower-level item from another factory that can use these feathers until we get that high up in levels? I hate having ducks and never wanting to feed them.

Ideas for feathers: quills for writing at the paper factory, feather earrings at the jewelry, some kind of clothing item at the tailors? Fishing lures at the plastics factory? Stuffing a furniture item?