Bouncy, colourful, soft and organic feeling, these little balls of sensory stimulation are a joy for the "touchy-feely" stimmer. They're also a fascinating little science demonstration for engaging bright young minds.
They start off tiny little coloured beads, like tiny dried peas about 3mm (1/8 inch) across. When you pop them into cold water they start absorbing it immediately and after 24 hours have become soft, springy balls of joy. They absorb around a thousand times their starting volume so those little balls grow to around 30mm ( 1¼ inches). A dozen or so can fill a 450g (1 lb) jam jar once fully hydrated.
Once they're ready they can be rolled, bounced, squashed, wobbled – your imagination is the only limit. If you squash them hard enough they'll squish into jelly, but when there are hundreds in the bag to start with, you can afford to indulge in a few squishy moments ;)