The younger sister said they were worms.
“What worms would glow like that?” her older sister asked, sneering at the thought that there could be living creatures in the pit before them.
“Glow worms,” the first girl replied. “We learned about them in zoology last month.”
Her sister rolled her eyes. “BS,” she said.
Their brother, sitting in between them both physically and in age, shook his head. He, too, was peering at the pit. “Not worms,” he said. “But something alive must be in there.”
“Is it even hot anymore?” the younger sister asked. “The fire went away and now there’s nothing to make it hot.” She bent down to put her finger in the middle of the scarlet and orange glow worms. Her sister reached across to stop her and pushed her back from the pit.
“Don’t do that, you idiot!” her sister said. “Of course it’s still hot there. Hotter than the fire itself.”
“Really?” the brother asked, looking up at her.
“Well, that’s what Dad says, anyway.”
This claim to the apparent wisdom of their father silenced the other two children. The brother took a twig from beneath his lawn chair and began poking and prodding the worms. “They’re like rivers,” he said after a while. “Little red rivers. See? The way they move. They must come from some lake–“
“Sure, sure,” his older sister said. “You’re a real genius. Going to award you the Nobel Prize for–“
“What do you think they are, then?” the boy asked, his eyes flashing and his face turning a menacing pink.
The older sister put a finger to her lower lip. She wondered if she should tell the truth, or what she thought of the truth, at least, to her siblings, or if she should invent something fantastical. Her brother and sister looked up at her, expectation written in their expressions. The older sister wished it would rain, a convenient deus ex machina that would extinguish the glow from the pit. But the night sky above her was clear.
At last, she opened her mouth to speak. “They’re just em–” But then she caught sight of her sister’s eyes. They were bent, pleading. On the verge of tears. Or were they hopeful? The older sister couldn’t decide.
“Never–never mind,” she said. “You’re right,” she said to her sister. “They are worms.”
Their brother gave a disgruntled murmur at this revelation but said nothing.
“Big, glowing worms. They light up because they’re using all this energy to try and escape this pit they’re in. But they can’t get out. So they get angry and burn up. That’s why they’re so hot.” The older sister smiled as she spoke, keeping her attention on her siblings.
Now, with triumph and vindication, the younger sister could speak without fear of rebuttal. The younger sister said they were worms.