If kitties are bored enough they’ll play with anything except for balls on their own, but they’ll play with any toy if they see it moving (if they’re a little bit bored and they’re in the mood to play with it!)
Kitties are only in the mood to do one “play” thing at a time (playing with toys, chasing kitties, chasing the cursor, scratching things, sitting in a box/bed, etc), so if they aren’t playing with toys they’re just not in the mood at that moment ^^