The $\pi$-meson is a boson, but consists of quark-antiquark (fermions). It seems to me that at some energy level (equivalently distance) the inner structure (fermionic nature of the quarks) of the particle in question should become important and the bosonic nature less so.
Can we have a bunch of pions occupying the same quantum state at all temperatures, or is this model bound to fail due to the fermionic nature of its constituents?
I'm thinking for example of the pion-cloud (in some models) surrounding the nuclei.
EDIT: I found this question which is very related to the present one. Although I should add that my question (regarding the pion-cloud) is more specific and less general.