  Motivated by a question of Baldi-Klingler-Ullmo, we provide a general
sufficient criterion for the existence and analytic density of typical Hodge
loci associated to a polarizable $\mathbb{Z}$-variation of Hodge structures
$\mathbb{V}$. Our criterion reproves the existing results in the literature on
density of Noether-Lefschetz loci. It also applies to understand Hodge loci of
subvarieties of $\mathcal{A}_g$ . For instance, we prove that for $g \geq 4$,
if a subvariety $S$ of $\mathcal{A}_g$ has dimension at least $g$ then it has
an analytically dense typical Hodge locus. This applies for example to the
Torelli locus of $\mathcal{A}_g$
