Let $H=(\mathcal{V},\mathcal{E})$ be a directed hypergraph, sometimes called a dihypergraph. Each vertex $v\in{\mathcal{V}}$ is incident to some hyperarcs in $\mathcal{E}$. Conversely, each hyperarc $E\in{\mathcal{E}}$ is incident to some vertices in $\mathcal{V}$. $H$ is Eulerian if there is a circuit $C$ such that each hyperarc $E\in{\mathcal{E}}$ appears exactly once in $C$. Similarly, $H$ is Hamiltonian if there is a circuit $C^{'}$ such that every vertex $v\in{\mathcal{V}}$ appears exactly once in $C^{'}$. We show that both of the problems are NP-complete. Some necessary conditions for a dihypergraph to be Eulerian are presented. We exhibit some families of hypergraphs for which those are sufficient conditions. We also generalize a part of the properties of the Eulerian digraphs to the uniform and regular directed hypergraphs. Stronger generalizations of \textit{Eulerianicity} to dihypergraphs are also studied. Finally, we show that the de Bruijn and Kautz dihypergraphs are Eulerian and Hamiltonian in most cases. We also study some properties of their bipartite representation digraph.
