These are a favorite at our house! We find them
at our local Dollar Tree (probably my favorite place ever). You can find them online here http://crystalwaterbeads.com/.
This is a great summer experiment for kids
3+. They are squishy and are excellent tactile play. They also last quite a
while. Our family did experiments with freezing them, putting them in vinegar, breaking them, and bouncing them. Add them to sensory
box!
Notes: They start very small and don’t get
very big, keep them away from small children and infants. They present a choking hazard. They take a while to get full size, part of our experiment we observed them as they grew overnight.