Why are composite particles grouped with force carrying particles? This
Huge confusion with Fermions and Bosons and how they relate to total spin of atom
says a hydrogen atom is a boson.
I'm confused. I thought bosons were force carrying - e.g. a photon, gluon, etc?
 A: Some bosons are force carriers as you have already noticed, however, a boson is defined as a particle (elementary, composite)that obeys the Bose-Einstein statistics (has integer spin).
In fact, we know a boson that is not a force carrier: the Higgs boson. Of course there are other composite bosons that aren't force carriers like the mesons.
Also, some bosons are force carriers because in the framework of quantum field theory they appear as propagators which mediate the interaction between particles. Some intuition about this can be built by reading about the Feynman diagrams.
A: 
I'm confused. I thought bosons were force carrying - e.g. a photon, gluon, etc?

The term "boson" and "fermion" define the spin of the quantum particle, integer for bosons, half integer for fermions. All such particles when modeled in a  quantum field theory can carry a force, a $dp/dt$, where $p$  is the momentum.
Photons, gluons and W's are gauge bosons, characterizing the potential entering in the quantum mechanical differential equations, as I discuss here.
