I can't imagine the efficiency that makes such long flights possible in such a tiny form factor. Compared to our drones, it must be multiple orders of magnitude more efficient.
The ones that landed here hadn't aimed for or planned to find the rig, they were just in the same physical location and found a space to land.
At the time, I tried to find information about it online, and all I found was an article about it happening on the other side of the Atlantic several years earlier.
A migration of the machines so to say.
I'm thinking systems that mostly exploit thermals and updrafts, engaging in a kind of bird like automated soaring.
sounds like they need to organize into political parties, strength in numbers
https://www.npr.org/sections/krulwich/2011/06/01/128389587/l...
Efficiency is a maximization of these ratios.