  We propose a means to discriminate between the two basic variants of Little
Higgs models, the Product Group and Simple Group models, at the next generation
of colliders. It relies on a special coupling of light pseudoscalar particles
present in Little Higgs models, the pseudo-axions, to the Z and the Higgs
boson, which is present only in Simple Group models. We discuss the collider
phenomenology of the pseudo-axion in the presence of such a coupling at the
LHC, where resonant production and decay of either the Higgs or the
pseudo-axion induced by that coupling can be observed for much of parameter
space. The full allowed range of parameters, including regions where the
observability is limited at the LHC, is covered by a future ILC, where double
scalar production would be a golden channel to look for.
