Let $\mathcal{G}=(G_{1}\rightrightarrows G_0)$ be a groupoid, where $G_{0}$ is the space of objects and $G_{1}$ is the space of morphisms. $\mathcal{G}$ is called etale if both the source and target maps $ s,t:G_{1}\rightarrow G_{0} $ are local diffeomorphisms. Being etale is $not$ invariant under Morita equivalence (equivalence of categories).
Could anyone give me a simple example of this fact?