After posting, I reminded my DH that - instead of saying to himself "how cute" when he saw them batting the things around - he should have taken the things away. After much searching, we found everything, thankfully, and have put a cover on the box.
3 weeks after adopting our older cat, she ate a length of a streamer type cat toy. $2,000 later, we had a healthy cat. It seems that these little creatures are so exposed to dangers.
The avatar is one of our cats. We think she's part Norwegian Forest Cat. Rumor has it that she wasn't the one who dragged everything out of the box.