The objects of a natural kind have yet undiscovered properties in common. Animate objects are to be understood in terms of their desires and actions. Inanimate objects are passive. Some objects are edible by humans and some are not. These kinds pervade the baby's environment.
Kinds belong to higher kinds.
Red is a color and color is a quality. This is a fact of logic rather than about the physical world, but its usefulness is dependent on objects being naturally grouped into kinds rather than being all completely different. There are sets of objects and other entities. This includes both sets of objects perceivable on a single occasion and sets organized more abstractly. Sets can often be counted.