MONROE — Last week, Doug Kinsman looked into the mailbox, and was concerned when he didn’t find what he was looking for.

There was only mail inside. Normally, that’d be fine. But he was there for a special delivery: two female Madagascar hissing cockroaches.

“So I was like, ‘Oh no, the mailman took the roaches as outgoing mail,’” he said.

He was grabbing the roaches as part of a socially-distanced dropoff with Xue Davis, another Monroe resident. She hadn’t put them in the mailbox yet, so she came out of her home to give him a small box, which had his name and a little doodle of a roach saying “nice to meet you” scrawled on it.

Davis, a program manager at Yale University, has a small bounty of the invertebrates after she was asked to care for them in March at the school’s Brain Education Day when she said they’d be used for a demonstration for kids to hear what neurons sound like when they’re firing.

The science outreach program was postponed because of the pandemic, so since then, the cockroaches have just been hissing around in a tank at home, multiplying into a “healthy thriving colony,” Davis said.

“I just have too many cockroaches,” she said with a laugh.

That’s what prompted her to reach out to other local residents in a Monroe Facebook group to see if they wanted to get in on the action.

“This is by far the strangest post I’ve made on potentially any Facebook group ever,” Davis wrote in a post on Sept. 10. “Are there any teachers who might want some for a class pet or educational unit? Or even just anyone who would like an interesting personal pet? I just have too many and would love to give some away.”

Kinsman was one of three people who have reached out to her about the opportunity. His wife sent him a link to the Facebook post, and the rest was history — he now has them set up in a little terrarium at home, right next to their crickets, for his three kids to observe.

“Growing up, science was always my favorite thing, and my dad was always really cool about doing fun stuff like that, so I kinda carried the tradition along,” he said. “I’ve gotten a few queen ants and started colonies, and we have a leopard gecko. I actually was talking to my wife a while back about getting these cockroaches and she was like ‘Eh, I don’t know.’”

Once she sent the link for the free giveaway, he figured that was the “green light” and proceeded with pickup plans. Now, the Kinsmans’ kids — Douglas, 8, Manuel, 6, and Vida, 3 — have been learning about how the roaches can scale glass, what their feeding habits are like, their life cycle and more.

When they picked them up, the names for the cockroaches were hotly debated, Kinsman said — Manny wanted to use some names from Transformers, but Vida got the final say: Their names would be Tiki and Diamond.

They’ve been testing out some different foods for the roaches to eat — strawberries, bananas, celery and carrots — and changing the temperature of one half of the tank to see which side they’d like more, Kinsman said.

“They’re super docile, they can’t hurt you, and they make that cool noise when they get disturbed,” he said. “You can handle them, the kids can handle them, you know, in a very careful environment.”

The Madagascar hissing cockroaches, as their name indicates, are known for the hissing sounds they make. They also get rather large — 3 or 4 inches long — and like to hide and climb on things, Davis said. They’re also not pests — of more than 4,000 cockroach species worldwide, only about 30 are deemed pests, according to Smithsonian Magazine.

They’re not totally without risk — they populate quickly, and could escape without a proper habitat — but they’re not likely to live long outside of their designated space, according to Newsweek. They do make “great, low maintenance pets,” Davis said.

“Keeping these kinds of insects are hobbies that functional grown-ups have, but when you’re younger, you might not have the opportunity to,” she said. “Like, when I was in high school, I wouldn’t have known where to buy these things or source them if I’d wanted to, and it doesn’t naturally occur to people that you can buy bugs on the internet.”

Now that they have the insects, the kids “love them” and look forward to having fun with them, Kinsman said.

“Obviously, they’re educational, but they’re cool,” he said.