We call them firelights. Never seen so many though.
Firelights is the name used to refer to bioluminescent insects native to Zaun.[1][2]
A group of Zaunite survivors who banded together named themselves after them. Though the insects were supposedly rarely seen in numbers, the insects took a liking to the home of this group, possibly due to the tree that flourished in their base despite being in Zaun.[1][2]
Jinx's weaponized firelight.
Meanwhile, Jinx experimented with several butterflies, mechanizing their body and wings to weaponize them into timed bombs. Jinx later unleased them, along with a swarm of firelights, on the enforcers guarding the barricade on the bridge to Piltover, resulting in a series of explosions that due to the insects' colors looked like a small, green fireworks display — a deadly one that resulted in the deaths of a handful of enforcers.[1]