Mission: Butterflies

Right, I'm trying to get some butterflies running (flying?) around in my scene.

My original plan was to animate the butterflies, then put them in a particle system and control it from there, however this won't work as animated meshes can't be used in the particle system. Here's what I have so far -

Here are my 3 plans which I will test out to find a better way of doing it -

Prefab the butterfly