We can't upgrade because there is not enough fishing. These fish are very picky about bait, and their habitats change rapidly.

Then in order to catch more such high-yield fish in a short time, gold bait (mole cricket, shrimp, pearl mussel, zebra mussel, bait fish) is needed.

Don't think that you can do whatever you want with bait. We still have to build a nest (if we don't make a nest, we won't concentrate on the fish's mouth), then we also have to build a nest.