  Given a graph $G$, an identifying code $C \subseteq V(G)$ is a vertex set
such that for any two distinct vertices $v_1,v_2\in V(G)$, the sets $N[v_1]\cap
C$ and $N[v_2]\cap C$ are distinct and nonempty (here $N[v]$ denotes a vertex
$v$ and its neighbors). We study the case when $G$ is the infinite hexagonal
grid $H$. Cohen et.al. constructed two identifying codes for $H$ with density
$3/7$ and proved that any identifying code for $H$ must have density at least
$16/39\approx0.410256$. Both their upper and lower bounds were best known until
now. Here we prove a lower bound of $12/29\approx0.413793$.
