Those chompers on the side are called mandibles. The mouth is behind it.
Paul Illsley has posted a number of high magnification portraits of insects and spiders at Tiny Faces in Nature. His collection includes this remarkable portrait of an ant, which gives a little better sense of what’s actually inside an ant’s mouth.
Does your little Caterpickle want to know more about ants? The ASU School of Life Sciences has an interesting web article explaining the various parts of ant anatomy and how different kinds of ants spend their days.
On a personal note, I had hoped that the end of summer would bring an end to the “Let’s ask Mommyo questions about bugs!” phase. Apparently not.