Preschool Science: Water Beads




Science with toddlers and preschoolers is as simple as encouraging observations and discussions. They are naturally curious about their world, and truly are little scientists… they wonder, they question, they test, and question again.

Capitalize on that by providing lots of materials and experiences about which to wonder. These water beads provide endless opportunities for discovery…

Water beads are simply hard polymer balls that grow several sizes when soaked in water overnight.

I got mine in a set of science experiments one year, but found these on Amazon. You can find them in some hobby stores (I saw some at both Michael’s and Hobby Lobby), or other places online.


water beads


First, we found a container to put our water beads in {we used a plastic shoebox with a lid}, a pitcher or jar of water, and the beads.

Molly poured them in the box and patiently let Logan play with them for awhile while she and I read a story together. Logan explored for awhile and then I asked her about them. She said that the balls were colored {and pointed out each color to me}, that they rolled and made noise, and that they were funny.

All fabulous observations from a 2 year old!


Dry Water Bead Observations


I asked the girls what they thought would happen if we added water to the box. Logan told me that the balls would splash. Smile Molly knew where this was going because she answered right away that they’d grow bigger.

To stretch her thinking a bit, and to remind her that scientists make a hypothesis {a word we love around here!} before they try something out, I asked her to tell me how the balls would be different once they grew, if that indeed happened.

Molly said that the balls would be slimy and that they would slip around. She also hypothesized that they would keep growing forever. Logan caught on at this point and repeated (again and again) that they would “get bigger and bigger and BIGGER!”

So we tested their theories:


Adding Water to the Beads

Adding Water

Feeling Water Bead Texture


Since nothing happened right away no matter how much they stirred, we put the lid on the box and placed it on a high shelf overnight. I left it alone for a bit the next morning; I wanted them to wonder about the experiment and tell me they wanted to check it out.

Within an hour after breakfast, they remembered their experiment. So we revisited their hypotheses and added guesses about the colors we’d see. Molly thought the colors would be gone, Logan thought they’d have gotten bigger and bigger and BIGGER!


Water Beads After a Night


The beads had grown, and the colors {though more muted} were still there. I spread the beads out on the light table and let the girls play with them.

Molly squealed at the “sliminess” and realized that her hypothesis had come true “just like a real scientist!” While Logan continued to play, Molly wanted to know how these balls worked:




So we talked a bit about polymers. Water absorbing polymers like these water beads are made up of chains of molecules. Water is very “sticky” because it has both a positively and a negatively charged end. The long molecule chain of the polymer gives water lots of opportunities to “stick.” The water is then absorbed into the polymer, which grows bigger.

I told her to think about the diapers Logan wears {hopefully not too much longer!} and how they get bigger when she pees. There is a water absorbing polymer gel inserted into the diaper that absorbs and traps the pee. {I have another polymer experiment planned for her to see this soon…}

That was about all she needed, and more than most four year olds would want, and she went back to playing with the beads.


Playing With Polymers 

Science doesn’t have to be intimidating, and it doesn’t have to be formal in the early years… the most important thing for toddlers and preschoolers is that they feel free to ask their questions and search for their answers. Let them explore!