Speculation/question about von Neumann probes

So, it's a pretty well known theory that many UFOS could be von Neumann Probes, aka, probes from distant civilizations, and I had some speculations about what they do.

When we see these lines of lights in the sky, they are usually moving and change shape or alignment, and I can't help but wonder what the purpose of these movements are. Could it be that these probes carry devices that must be positioned in a certain way in order to capture data? What could these probes be looking for? Would ET's have interest in climate and and biology changes?

Does anyone have any ideas as to what exactly these different civilizations may be searching for?