After Alice joins you, the Nebula Pillbugs event can be played.
After heading to one of the locations where the event takes place, a large Nebula Pillbug will hop onto your boat. Speak with Alice to start the event. The Pillbug will release its children over the boat, allowing Stella to run around, collect the baby pillbugs and return them to the mother (giving Stella 1 nebula fiber per bug). Some of the baby pillbugs will glow and run around excitedly; if caught in this state, they return 2 nebula fibers.
Once all the baby pillbugs are caught, the mother will hop off the boat and the event ends.