Eddy models. This is a boy hammy; notice the enlarged lower region (which is not always visible) and the spacing between the penal opening (top) and anus (bottom-darker hole).

This is Eleanore modeling. Notice the absence of testicles and the closeness of the two holes. The vagina is the upper one and the anus is the bottom. Also, notice the dark dots on the belly--teats. The dots on the belly are the first indication on young pups as to their gender.