C.J. will just purchase fish after each challenge, while Flick will acknowledge creepy crawlies available to Animal Crossing Items be purchased immediately.

Both show up haphazardly on the island, acknowledge commissions for critter-roused designs, and are consistently available before 5 AM. Continuously organize markup over the SRP (recommended retail cost) for most extreme benefit.

On the other hand, in case you're not keen on LOLGA selling bugs and fish, you can generally give them to Blathers for show in his gallery or keep some for your hidden assortment.