Fireflies

"They're like little fires in my pocket!"

- Willow

Fireflies are bugs that glow faintly at Night, and can only be caught by a Bug Net. They do not respawn, thus making a finite amount of them in each world. Fireflies become visible and can normally be caught during the night, but are also catchable while invisible during the day - by pressing Spacebar. Fireflies can only be found in Forest and Grassland biomes, unless released by the player in another area.

Standing in the fireflies' light resets the timer in which the Grue will attack during the night, though the light from fireflies will disappear until the player leaves their vicinity. If the player does not have a source of fire, he or she may "firefly hop" between three of four groups of fireflies for survival during the night. This can still be dangerous, as sanity will drop significantly.

Releasing fireflies near the Fire Pit or other key locations in your base camp might come in handy, as glowing light will indicate their positions in total darkness of the night.

Fireflies will take up space, so the player is unable to build there unless they are caught.