Exploring texture and the world around them is what "busy toddlers" are all about. After my son and I made the snowman craft yesterday my daughter wanted in on the action. She loves to paint but had already painted that day what she really wanted to do was play with the salt.
So we did.
I poured kosher salt into a tray and let her go. We used some water color to make it blue then green ( just a dab of water color on a brush will do) .
I didn't intervene too much, sitting with her every now and then asking is it rough? Does it feel hard on your hands? Does it make noise on the tray?
It wasn't a long activity - none with 18 month olds are, but it was a new experience and that is what exploring is about.