Billy thinks we don't let him chase feathers often enough or for long enough. So he took matters into his own paws.
I was in the kitchen making tea and heard a clattering noise from the dining room. Turns out that Billy knocked a feather and its associated rod off the bookshelf -- we didn't know he could reach that shelf! -- and was happily batting it around on the floor.
Time to find a more secure location. Noise aside, we don't want him swallowing the string at 3 AM some morning.