The bubble size of silver carp and bighead carp is uneven. As big as table tennis. When the water surface is calm, if a layer of "foam stars" with a large diameter appears on the water surface, it is often silver carp and bighead carp that sneak into the nest. Especially when fishing in Taiwan Province. The powder bait is atomized quickly into water and has a good effect of attracting fish. When the fishing point is "Fish Star", the fish will not take the bait. When the bait lead sinks, large bubbles often appear. This is a "fish star" produced by silver carp and bighead carp turning up silt when they enter the nest and escaping from the bottom when they are frightened.