At Seth Low Intermediate School 96 on Monday in Brooklyn, New York, Dominica Fiume’s second-floor science and zoology classroom was beginning to have that hollowed-out, end-of-the-year feel.

The 55-pound African spurred tortoise was already summering at Fiume’s home in the Poconos, leaving his 8-by-8 foot enclosure sadly empty. The little Russian tortoise had gone home, too, along with the rabbits and the guinea pigs and one of the chinchillas.

This left only the other chinchilla, the bearded dragons and the 2-foot-long blue-tongued skink, and the ball python and the albino corn snake, and the parakeets and the doves, and the leopard geckos and the six aquatic turtles and the African clawed frog, all variously chirping and barking and slithering and blobbing around in their cages and tanks.

Across town on the Upper West Side at Public School 87, Michael Ziemski’s kindergartners were enjoying one of their last hands-on sessions of the year with the class’s hundreds of creepy crawlies.

“Who wants a worm?” Ziemski asked. “Me!” three voices called out at once.

And in Sunset Park, Brooklyn, 8-year-old Charlie Mitkowski has started his new job as summer custodian of the Brooklyn Apple Academy’s two resident gerbils.

As the year winds down at the city’s schools — Tuesday is the last day for public schools — art projects come off the walls, final grades get figured and yearbooks are signed. But it’s not just teachers and students getting set for vacation. The uncounted thousands of classroom pets that have taught lessons about life, death and peaceful coexistence are headed into summer, too.

It has been a year of additions and subtractions in Fiume’s classroom, some of them related. In September, the teacher brought in two white mice, a male and a female. Soon there were 13 more.

“But after a while it was like, we didn’t need 15 mice in the classroom,” she said. “And I told the kids, ‘You know what these are for, right?’ And everyone was like, ‘Yeah.’”

They were for Zig Zag, the little albino corn snake.

“Every once in a while,” Fiume said, “the kids would come in and another baby mouse would be missing.”

Fiume, 45, started her classroom menagerie in 2003, shortly after arriving at IS 96, which serves a polyglot immigrant neighborhood, and discovering that nearly a third of the students spoke little English.

“After a few weeks I said to the principal, ‘I think I’m not reaching a lot of these kids, I think they’re not getting my lessons. Can I bring in my pet rabbit from home? Maybe it would help them make a connection.’ Next thing I knew, he called a retired teacher who used to have animals in the classroom, and suddenly I was surrounded.”

Now the 30-critter zoo has literally outgrown the classroom. In September, Fiume is moving downstairs so that Bentley the giant tortoise can have a bigger pen. And there’s no telling what students and parents might bring to her doorstep next year.

“It’s hard to say no,” she said, looking around at the animals.

It’s baby season in Ziemski’s kindergarten class at PS 87. The Madagascar hissing cockroaches recently produced offspring — maybe a couple of dozen, maybe many more. The painted lady butterflies, having emerged from their cocoons, were released the other day. The clump of moss in the terrarium that sat relatively inert for several years is suddenly teeming with tiny snails.

But the children’s perennial favorites are the redworms, thriving in their big bin of dirt. On Monday morning, Ziemski handed them out on paper-lined trays.

“The worms smell bad!” announced Lea Mansson.

“Like garbage!” her tablemate Charlie Post said approvingly as one crawled on his arm. He examined it through a magnifying glass. “I see blood leaking out of him,” Charlie said. “Just a little bit.”

Next to Charlie, Anastasia Fernandez, wearing a crown, asked Ziemski for another worm. Hers was gone.

“I put water on it and then it drowned,” she explained. “I threw it out.”

With 5-year-olds, Ziemski said, casualties are inevitable. “We lose one or two worms every time we take them out,” he said. “Not bad.”

Ziemski, 61, said the students’ enthusiasm extended outside the classroom. “Now when we go to the park, some of the kids will spend their time lifting up rocks and looking for bugs and worms,” he said.

Fiume, the middle school teacher, said her animals had helped bridge the language gap with her English-language learners, and she said some students with behavorial issues were calmed by the presence of a skink or a chinchilla.

“The special-ed kids love them,” she said. “It helps them stay focused.”

While the city’s Education Department does not keep figures on how many public school classrooms have animals, the most recent science curriculum for the primary grades urges schools to integrate animals into the classroom experience.

At Brooklyn Apple Academy, a drop-in resource center for home-schoolers above a bar and grill in south Park Slope in Brooklyn, the director, Noah Apple, said it could be challenging to keep the children, who range in age from 6 to 13, engaged with the animals.

“As far as kids and pets, there’s the initial burst of excitement, and then there are long periods of ignoring them,” he said. “The fish have been pretty much ignored.”

To address the issue, Apple, 34, pays the students in the school’s local currency, Apple Bucks (honored at local businesses and backed by actual dollars from parents), for helping out with chores. “$1: Refill hamster/gerbil water,” the sign on the wall reads. “$5: Clean hampster/gerbil cage/fish tank.”

For summer, the academy’s furred and finned residents were bound in different directions.

The tadpoles one girl brought in, having survived to froghood, were being released in the pond in the Catskills where she had found them.

The gerbils, one white-gray and one black, known variously (to different students) as Lightning and Thunder or Curious and Shadow, are at Charlie Mitkowski’s apartment. They are his first pets. He has named them Smoky and Onyx and bought them an exercise ball.

“Basically, most of the time they’re hanging out in their burrow, so that’s what they’ll be doing for the whole summer,” Charlie said.

© 2016 The New York Times Company