DAUPHIN COUNTY, Pa. (WHTM) — They are as spectacular as they are endangered, and a few more migrating monarch butterflies now carry a sure sign they’ve passed through central Pennsylvania.

How far will they really go though?

Well, one “tagged” with a small sticker — carrying a unique identifier, three letters, and three numbers like a car license plate — at Fort Hunter in 2015 was found in Mexico in 2016.

Jane Webster, a now-retired environmental educator, remembers being “ecstatic” when she ran across the butterfly’s unique code on a list of those whose tags had been documented in Mexico.

“When you find one of the numbers that you recognize as one that you released, it’s like, ‘What???‘” Webster said. “So it’s way cool.”

Webster spoke Tuesday at a tagging event, where current environmental educators Richelle Corty and Savanna Lenker taught adults and children about the migratory butterflies — and tagged and released three of them.

After affixing the stickers, Corty put each butterfly on a child’s hand, and then the butterfly flew.

“It was kind of ticklish and also kind of fun,” said six-year-old Ronen Match, describing a butterfly’s brief stay on his hand. “And then it went away.”

What should people of all ages know about endangered monarchs? You can ask one of the educators — or one of the educated children.

“They need habitat,” Ronen explained. “Which I think is one of the things that’s slowing down the population of monarch butterflies. They don’t have as much milkweed as they need.”

That’s true, grown-ups confirm. Why?

Well, monarchs at all stages of life — including days-old caterpillars at the event — thrive on milkweed nectar. But milkweed can be toxic to birds. So monarchs loaded with milkweed nectar can be toxic to birds, which is a good defense when you’re trying to get eaten.

How good a defense?

Ask another young expert at the event, eight-year-old Abriana Kaplan (yes relation — she’s the reporter’s daughter).

“Well, there’s this other type of butterfly called the viceroy, and they mimic monarchs,” Abriana explained. (It’s true — the internet is full of articles to help decipher one from the other.) “So when a predator sees them, they won’t attack them, because they’ll think it’s a monarch.”

Abriana spoke while wearing a Wild Kratts t-shirt; you could do worse than wagering the children’s show is where she got her information about the monarchs.