A Valentine sound-matching activity that I made for Kitten. I bought a set of 4 red and 4 pink heart-shaped boxes. Then I filled 4 red hearts with different things and 4 pink hearts with same things to make red-pink pairs. You need to make sure that all materials you use make different noise when shaken, it was harder than I thought as all small objects made a very similar noise, as did all larger objects. I ended up using rice, small wooden bowls (for toys, got them at Hobby Lobby for a completely different project, but I have some left over), rubber bands and one large jingle bell per box (small ones unfortunately didn't make enough jingling noise). Then I taped around the boxes. Very important! I supervise her every time she plays with these since she is capable of peeling the tape off and some objects may be a choking hazard! I guess you could glue them shut but I wanted them to be reusable. I demonstrated how to find matching pairs and even though Kitten doesn't completely understand the goal of matching, she enjoys it nonetheless.