Hand a child a bowl of slime and tell them it’s monster snot, and you’ve somehow improved the activity considerably. Add plastic eyeballs, and you may have achieved greatness.

Kids’ enthusiasm for all things disgusting can mystify adults. Why do poop jokes get funnier with repetition? Why is fake blood a revelation, rather than revolting? And why would anyone willingly plunge both hands into a bowl of cold spaghetti labeled “witch guts”?

As it turns out, our sense of disgust develops over time. And the stuff that makes adults cringe gives kids opportunities to explore their senses, test boundaries, experiment, and discover what makes people laugh.

Kids are natural-born mad scientists

Ever watched a toddler investigate something disgusting with zero hesitation?

“Disgust is not innate, not present at birth,” explains psychologist Paul Rozin in an interview with the American Psychological Association interview.

A September 2026 study involving 3,050 parents in the U.S. and U.K. examined how children’s germ-avoidance behaviors develop during their first 10 years. Researchers found that behaviors such as putting objects in their mouths and touching dirty surfaces were most common in infancy and toddlerhood. Disgust responses and hygiene habits developed later, with notable shifts around ages 2 and 4.

Of course, not every child enjoys sticky, slimy, or smelly sensations. But for many, investigating unfamiliar textures is part of discovering how the world works.

The forbidden word is always funnier

If your preschooler has discovered the word “butt,” you may be in for a long year.

The American Academy of Pediatrics explains that toilet humor is particularly common among 3- and 4-year-olds. Children are learning about their bodies, discovering words adults treat differently, and enjoying the reactions those words provoke.

Developmental psychologist Doris Bergen offers a wonderfully straightforward explanation in another APA interview: “Bathroom stuff is one of the few ‘shocking things’ that you’re not supposed to talk about.”

In other words, children are discovering the comic possibilities of breaking a social rule without doing anything particularly terrible.

And humor has a social dimension. A 2025 study published in Communications Psychology explored connections between humorous peer play and children’s social understanding. Joking around gives children opportunities to notice how others respond and experiment with shared amusement.

So the next time your child announces “poop sandwich” and dissolves into hysterics, remember: they’re experimenting with language and social reactions. Whether the dinner table is the best place for that experiment is another matter.

Gross play can be surprisingly educational

There’s also a reason children love plunging their hands into pumpkin guts, squishing mud, or mixing mysterious substances in a bowl.

Messy play engages multiple senses while inviting children to experiment. What happens when you add water? Why does this mixture stretch? Can you make something that looks disgusting but tastes delicious?

“Sensory play supports nearly every area of early childhood development,” writes Dr. Rebekah Benedum, senior director of programs at Catherine Hershey Schools. “Unlike activities with step-by-step instructions or a ‘right’ answer, messy play is open-ended. Children decide what to create, what to test, and what to try next.”

Messy play also creates opportunities to practice fine motor skills, make predictions, solve problems, and use descriptive language. And for some children, squishing, squeezing, and stirring provide a soothing outlet for feelings they may not yet have the words to express.

Five delightfully disgusting October activities

Halloween offers the perfect excuse to indulge your child’s gross curiosity. Here are five experiments worth trying:

1. Make a mystery guts box. Fill opaque containers with cold cooked spaghetti (“witch intestines”), peeled grapes (“eyeballs”), Fritos (“monster nails”), and damp sponges (“dragon skin”). Have children reach inside and describe what they feel before guessing the contents.

2. Conduct a pumpkin autopsy. Before carving your jack-o’-lantern, investigate its insides. Count the seeds, examine the stringy pulp, compare textures, and predict whether the seeds will sink or float. Older kids can weigh the pumpkin before and after scooping. And when the investigation is over, roast the seeds for a delicious snack.

3. Open a monster slime laboratory. We know what you’re thinking: Absolutely not in my house. But hear us out. Mix two parts cornstarch with one part water in a rimmed baking tray, and you’ve got a delightfully gooey substance that’s solid when squeezed and liquid when released. Let kids experiment with the proportions, preferably at a wipeable table, wearing old clothes. Skip the food coloring to avoid stains, and toss the leftovers in the trash.

4. Cook something revoltingly delicious. Try your hand at a few creative Halloween treats. Turn bananas into ghosts, decorate deviled eggs as monster eyes, or make edible “dirt” from crushed chocolate cookies. Let kids invent their own gross-sounding menu and prepare it together.

5. Create a potion station. Set out baking soda, vinegar, food coloring, and washable containers. Let children predict what will happen when ingredients combine, then investigate the bubbling reaction. Adult supervision keeps the experiment safely contained.

Let them get a little icky and sticky

Adults see pumpkin guts and think about the cleanup. Kids see something wonderfully strange to investigate.

And maybe that’s part of the appeal. Children haven’t yet learned to recoil from everything adults consider disgusting. They can approach a bowl of goo with curiosity, delight, and absolutely no concern for the kitchen floor.

So this Halloween, roll up your sleeves, put down a washable tablecloth, and join the experiment. You might discover that getting gross is half the fun.