Micro -
A definition of bait is provided in fishing regulation under Statewide Definitions.

Bait: "Anything that attracts fish or shellfish by scent and/or flavor. This includes any device made of feathers, hair, fiber, wood, metal, glass, cork, leather, rubber, or plastic which uses scent and/or flavoring to attract fish or wildlife."

If it has scent then its bait - that simple. Many of the plastic baits are either scented or have salt.

Tight lines
Smalma