The idea of a collective consciousness (or anthill) species is pretty simple; instead of cells tissues and organs you have ant-like creatures, all making up a larger creature. This is different from a hive mind in that the individuals of the mind are not sapient, only the collective is.
As I design this species and their culture, I realized a problem. Since they exist as a mass, they cannot use tools in the way we do. They are able to finely manipulate objects even better than us, but I cannot figure out how they could use tools such as hammers, or pickaxes. This creates a problem of them getting into and past the stone age and thus into civilization. How can an Anthill species be able to use tools?
Keep answer regarding the realism of anthills here