WATERLOO — A somewhat anxious crowd filled the room at the Five Sullivan Brothers Convention Center on Tuesday.

Hushed voices could be heard asking “Did you say snakes?” and “What if it escapes?”

But Elinor Roberts, 4, couldn’t wait for the show to start. She fidgeted, getting in and out of her chair, leaning against her mother and keeping her eyes on the gentleman at the front of the room.

When Jordan Walker, science educator with the Grout Museum District, began his presentation, Elinor was all ears, raising her hand often to answer questions Walker asked during his 30-minute show, “Snakes.”

The Grout was one of more than 60 exhibitors participating in the fifth annual Cedar Valley Family Stem Festival.

Walker, who has taken part in the festival since its inception, was there to introduce three of the Grout’s snakes to the crowd, including an 8 1/2 foot granite albino Burmese python.

It created quite a stir.

Elinor watched as Walker carried the snake around the room so audience members could pet it, swiveling in her chair so as not to lose sight of it. She exuded an excited energy as she waited for her turn, but was all business when the snake appeared in front of her, sitting up in her chair and touching the reptile with a straight face.

“Cool,” she said under her breath.

In the large lower level exhibit space, dozens of tables were surrounded by family members waiting to experience activities, experiments and demonstrations focusing on science, technology, engineering and mathematics.

“I have a feeling this is going to be good,” said 5-year-old Daniel Juza of Cedar Falls as he approached a table where Bob Strohbehn with Monsanto was dissolving dry ice in large tubes of colored water.

After some gentle urging, Daniel reached out to touch the gas rising from the tubes.

“Kinda cold,” he said.

This is the first time Strohbehn, a retired scientist, has participated in the festival.

“I think it’s cool,” he said. “It’s great to get the kids excited about science.”

At another table, siblings Clayton and Claire Northey waited in line to make “slime” out of glue, baking soda, food coloring and saline solution. Claire, 8, stirred the mixture as instructed. Clayton, 10, watched over her shoulder.

“It’s really squishy and pokey. It’s not sticky or bouncy, but kind of stretchy,” said Claire, who is a bit of a slime expert. “I watch slime videos on YouTube.”

“It was fun,” Clayton said. “It’s way stickier than I thought.”

“The more you play with it, it comes together,” his sister advised.

Further down the row of tables, Adrian Carter, 6, called his dad, Richard, over to help him build a structure out of toothpicks and gumdrops.

“Remember, you need a strong base,” his dad said as he showed him how to shore up his creation.

“This is great for them,” he said. “Teaches them how to build things, create things.”

The Carters attended last year’s STEM festival and decided to return.

“My daughter, Olivia, (a fifth-grader) is really into science and math,” Richard Carter said. “She wants to be an engineer.”

In the upper level exhibit space, area robotics teams drew a lot of attention. Jacob King, Josh Borwick and Greta Heistad, all seniors and members of Cedar Falls teams, enjoyed seeing the children’s reactions to their robots.

“We hear a lot of ‘I can drive this?’ and ‘This is so cool!’” said Heistad. “This is an outreach, trying to get them interested.”

“We come every year,” Borwick said. “The response has been great.”