Unless your thesis is, consciousness is only possible when God does it, then I fail to see the logic; besides I think you mean a design without a designer, otherwise it's a meaningless attempted tautology.
How is an anthill "intelligent"? I think you're confusing the anthill with the ants that are in it.
You're missing the point, or you're being deliberately obtuse, a single ant is neither intelligent nor, arguably, conscious, yet as a colony they can build structures with air-conditioning and a farm and waste disposal and etc. clearly a design with a designer.
Much like a single human couldn't create our modern society, with all it's convenience.
All of which seems to scupper or directly contradict your hypothesis.