I'm more thinking along the line of replace 'rat' with 'human'. We could all form a living peer-to-peer (in every sense of the phrase) network.

or vehicles. like car parasites . so this thing like attaches to a car and transmitts pirate software over wi-fi or hosts other free software. it can change host cars by itself if needed.

It would need be a robot that can attach itself to a rat, then de-attach and hunt for a new rat when that one is dead. Because rats have very short life spans.

So what we're really looking for is a rat parasite robot.

A rat's life span of about three years seem adequate to me. I guess the electronics won't even last that long in such an environment.