Manmade equals natural just as surely as a bird’s nest is a natural product.
So, the term “manmade”, may denote a certain class of artifacts that were fashioned by human beings, but those artifacts are as natural as can be.
The term “artificial intelligence”, is a misnomer in that intelligence is a concept that transcends the medium that is being used to express “intelligent principles”. “Artificial” describes a class of intelligence machines built by human beings that store intelligent principles for later application. However, creations of human beings are all natural, which includes our worldwide computer networks. The internet is as natural as a bird’s nest.