It is true the fuller they are the more picky they will be, but the liver I havent seen them be able to resist very often when schooled up. You still got to be as discreet as possible though.
They will eat all kinds of baits, lures, etc but not when they know your around. They get very smart, especially the pellet trained ones who interact with humans regularly. They get caught quite a few times when they are young and then they start catching on.....
