  A dominating set $S$ of a graph $G$ of order $n$ is a subset of the vertices
of $G$ such that every vertex is either in $S$ or adjacent to a vertex of $S$.
The domination polynomial is defined by $D(G,x) = \sum d_k x^k$ where $d_k$ is
the number of dominating sets in $G$ with cardinality $k$. In this paper we
show that the closure of the real roots of domination polynomials is
$(-\infty,0]$.
