This can be an easy question and it can be a difficult one, it all depends on the mood of the bass. However, finding out the forage in the lake can be relatively easy, and that will make finding out what to throw that much easier.
First, with very few exceptions, all lakes have crayfish, everywhere you go in the country bass are going to eat crayfish. This is why
jigs perform so well anywhere and everywhere. This goes the same with bluegill, most everywhere you find bass, there will be some species of brim or Bluegill.
You also really need to consider, are there some type of shad or other baitfish in this body of water? If you are pond fishing, don’t bother with shad. All you need to worry about is the bluegill, that is the primary forage in most ponds.
That being said, bass will eat almost anything they can get in their mouths. I have witnessed bass eating small squirrels, chipmunks, snakes, birds, other bass, mice, frogs, etc. They are opportunistic, predatory feeders and will take a shot at anything that they can fit into their mouth, and sometimes even what they can’t get it into their mouth.
Now it may sound like we’re simply referring to largemouth bass, but we’re not.
Smallmouth bass share very similar if not identical eating behavior as largemouth.