Use cadavers for moist egg incubation due to numerous aquatic predators in closed environment with limited bodies of water?
That would require land scavengers to be quite rare.
If there were numerous frogs, payload delivery would only need few successful splat-and-runs and then just wait.
There would also have to be local hairless naked prey animals with big enough body cavities.
You like naps? Because with lunch like that is be what you'll have.