Have you tried playing with water beads yet?? It is definitely one of the coolest trends in sensory play. Mack (3 years old) LOVES playing with water beads. Everything about the process in which they expand, how difficult it is to see them in water, and how they feel in your hands completely fascinates him. These are actually used more commonly in floral arrangements but in my house they are exclusively for play 🙂 You can purchase them at any arts and crafts store but I got mine off of Amazon. The only thing I will warn about is that they are not meant to be ingested, so best to use these with older toddlers or at least under strict supervision. I let Ava play with them but was constantly keeping them out of her mouth. I have seen some people using tapioca pearls as a great edible alternative
however have not tried them myself; although after seeing how much Ava enjoyed them, and wanted to eat them, I think that might be in our near future.