A "sensitive plant" mystery

A few days ago, I was standing near my weedy and overgrown mixed border.  I could hear little clicking sounds all about.  Just as I looked in the direction of one click, I would hear one in the opposite direction.  I first assumed I was hearing grasshoppers or crickets or some sort of insect making a clicking noise.  I kept observing and listening.  I think my first clue was not seeing any insects, and maybe I actually heard the miniscule shower of seeds hitting surrounding plants.  I was amazed to realize the clicking sound was made as the seed pods of the weed known as partridge pea or sensitive plant (chamaecrista genus, possibly chamaecrista nictitans?) burst open and spewed their seeds about.  I was amused and in awe.
If you've ever walked through a patch of these plants in the summer, you might have noticed how the foliage kind of withers in response to being touched or brushed against.  Some species are more dramatic than others.  I remember working in a youth program in the Uwharrie Forest and noticing some plants with larger blooms and a much more immediate and dramatic movement (possibly chamaecrista fasciculate?) than the ones that grew around our house.  If you stop and think about it, most movement done by a plant is so slow you can't actually watch it happen--the budding of leaves, the adding of another year's growth.  It's fascinating to see a plant that can make a quick movement.
It's also interesting to me that there were particular plants that I "liked" as a child.  The sensitive plant was one of them.  I think I might have thought the leaves looked a little like miniature palm branches (I could reenact Palm Sunday on a miniature scale) or mini mimosa branches.  I think my older siblings or my mother showed me how the leaves withered in response to being handled.  I'm pretty sure I thought that was cool.  I also liked the tiny yellow flowers that grew underneath the foliage.  I had favorite colors, but I also had favorite "shades" of colors and favorite combinations of colors.  That shade of yellow was particularly gratifying to me, especially against the green foliage.  I think we also liked any plant that formed pods, too, because we could use them as pretend food in our imaginative play.  It's a nice plant that I liked then and I like now, though I do treat it as a weed for my compost pile now.
Here is a close-up from my border of the dried pods--some closed, some curled after spewing their seeds.  Clicking mystery solved.