This Edible Glow-in-the-Dark Oobleck is a fun sensory activity for kids who are getting over a fear of the dark!

For years, every time I tried to provide Ella with a glow-in-the-dark toy or activity she would freak out and leave me sitting in the dark, alone.

No matter how fun or inviting the activity, the minute the lights were off or a door was shut, she was done. But, when she started to show a bit more bravery with going into a dark hall independently or not needing me to turn on the bathroom light for her, I wanted to reward and encourage that bravery with a fun glow-in-the-dark activity.

She was even more excited to share the activity the next day with our daycare kids and her excitement made them brave enough to face the dark, too!

This Edible Glowing Magic Mud was a fun activity for our entire daycare crew – all of the kids were entranced by the silky, silly sensory substance and glowing blue color and we were able to include even our youngest kids in our play.

Of course, this glowing edible mud didn’t taste great and I don’t think a belly full of cornstarch would make anyone too happy, but using edible materials for this activity made it so I didn’t have to worry about our little ones tasting the “mud” or touching their mouths after playing.

After the kids are done playing, the bathroom (or whichever room you play with the oobleck in) will look like something out of CSI but it’s super easy to clean up. You can either mop it up right away or wait until the oobleck dries and just sweep it up.

If you like this fun edible glow-in-the-dark oobleck, check out my friend Stacey’s edible glow-in-the-dark slime. She’s my co-author for The Slime Book:

(Read more about The Slime Book and what it contains here.)

Check out our quick video for how to make this fun glow-in-the-dark magic mud – and then scroll down to get the printable recipe and find out how to make this with potatoes instead of cornstarch!

Materials Needed for Glowing Edible Mud

• 2 cups cornstarch
• 1 cup tonic water
• Flashlight (or smart phone with flashlight setting)
• Blue marker
• Transparent tape
• Large container

Tip: my kids didn’t get bored of playing with this after two 30+ minute play times but you can add in scoops, spoons or kitchen tools to extend the play if your kids get bored.

How to Make Glow-in-the-Dark Magic Mud

In a large container mix the cornstarch and tonic.

(You can increase the increments as much as you want to make a bigger batch.)

Adjust the consistency to be solid when you hit the liquid firmly, yet let your fingers sink in easily when moving slowly. It should hold a form when rolled but quickly melt once you stop moving your fingers.

Take your phone or a flashlight and place a piece of tape over the light. Draw with blue marker over the tape. Repeat with 2-3 more pieces of tape to turn your flashlight into a cheap and easy blacklight.

Turn the flashlight (or flashlight setting) on and bring the container into a dark room. Close windows and doors and turn off lights to get the fully glowing effect.

If the mud starts to clump or dry out, add a bit more tonic water.

You can store in the fridge for a couple days but will need to adjust the consistency a bit before playing.

Pin this easy Glow-in-the-Dark Sensory Play idea:

Grab your free printable instructions for our edible glowing mud recipe:

How to Make Edible Glowing Oobleck with Potatoes

The inspiration for this recipe was this idea from Grant Thompson, “the King of Random.” This is his recipe video using homemade potato starch instead of cornstarch.

Are your kids afraid of the dark? Do you think they’d warm up to the idea if they could play with this fun glow-in-the-dark oobleck?

For more fun sensory play ideas, check out our muddy worm sensory bin or our fluffy slime recipe.