Junk to Funk: DIY Percussion

In my work as a music educator, I've often had to think on my feet, and improvise when a planned lesson goes off the rails or a schedule change forces a complete left turn into some other activity.
One of the things I came up with early on for my general music students was to do a scavenger hunt, looking for things that sounded interesting and could be turned into percussion instruments: drums, shakers, rattles, and metallophnes. The results were sometimes funny and always interesting.

To this day, I continue to look for interesting things that can be turned into percussion instruments.
Last week, I rode past a construction site and noticed dozens of odd plastic discs lying on the ground among the piles of wood scraps. I pulled my bike over, and gathered up as many as I could find. Shaking them in my cupped hands, I noted that they had potential as a percussion instrument, and took them home.

After rinsing them off (by letting them sit out in a few days of rainfall in a plastic potting pail), I poked a small hole in each one with a nail. Fashioning a handle out of some old bicycle cable housing, I attached the discs to the handle with some zip-ties, which I'd also found for free and saved.

The result looked whisical and sounded soft, and gentle. I imagine using it in a studio setting with a good microphone; and in fact I'll probably use this one on my upcoming album that I plan to record in late summer. I used a homemade shaker and a sistrum on my second album to great effect.)

What household objects are lying around your place that could be turned into percussion instruments?