Groton — Kaya Giesing and Lilliana Doak built a crocodile from Legos, put a motor in it and programmed their creation to chomp.  

"It can actually eat the Lego people, but don't put your finger in it or it'll chomp it," Lilliana, 8, warned.

The students attend Catherine Kolnaski Magnet School, which this year expanded Lego robotics — typically offered to older elementary school children as an after-school activity — to grades 2 through 5.

"It is a great integration of engineering, technology and mathematics, and it gets our students into the world of (computer) coding," Principal Christine Dauphinais said.

The intra-district magnet school enrolls 344 children in grades kindergarten through 5, including 66 magnet students.

School staff helped shape the magnet program, but Groton as a district is trying to make its schools more competitive and draw students back if they've left for similar programs elsewhere.

Lego robotics at the school places children in pairs. The teams then build a Lego model, add programmable parts like motors and sensors, and use computer codes to make their "robot" do what they want.

"They have to use problem solving, they have to use critical thinking, and they always work in pairs, so they have to collaborate," said Benjamin Moon, science, technology, engineering, arts and math specialist at the school. "It's super engaging, but it can also be super challenging."

Ny'Asjha Hudley, 9, worked on a plane during class Tuesday. She and her classmate built a bird earlier that was supposed to flap its wings, but they put a piece in the wrong place and it didn't work.

"We have to pay attention," she said. "Look really closely."

Third-grade robotics class began with Moon offering brief instruction, then students working in teams and consulting with Moon as needed.

The children had stackable green and red cups that they could use to silently check in: Green on the table meant they were fine on their own; red meant they needed help.

Moon reconvened the class at the end to discuss their progress.

The magnet school turned a room into a "discovery lab," for Lego robotics, though other teachers book it as well for lessons. 

The school designed it to look like an engineering lab with bench-style tables, lab chairs on rollers, Lego kits and laptop computers.

"They come into this room and just by the look of it, it gives them a different feel," said Moon.

The robotics program adjusts for age and skill. Fifth-grade students have built robots with a "brick" or "brain," which they can direct in multiple ways.

Luca Ursini, 11, explained: "You have like a headquarters where you have all of your programs and you can choose. My favorite one is the one where you have a flashlight and you flash it on it, and it makes it go faster."

"The kids go crazy for this stuff," Moon said. "It gives kids another reason to love school, and again, we hope that bubbles over into other areas."

d.straszheim@theday.com

Twitter: @DStraszheim