Nothing to do with lore, just an observation but your post triggered a thought. The infested design are based around insects, nidus in particular but what animal in nature most closely resembles a machine? Insects. Exoskeletons, segmented eyes like a camera, Omni directional flight, hive mind etc
On a side note I'm really drawn to the infested weapons, nidus frame and overall design aesthetic in warframe for some reason. It's completely unique, alien looking and it reminds me of the flood from halo. Would love to see DE expand on the infested even further in the future.