I read an article years ago (at least ten years back, possibly as much as 20) in the Philadelphia Inquirer (the local paper of note) about attempts to bug with bugs. Researchers attached tiny cameras and microphones to cockroaches. The idea was to sever the roaches antennae and use attached electrodes to guide them instead. It was a brilliant idea. Roaches can get into almost anywhere. They are very hard to find and kill. Even if you see a roach, your first thought is not “It’s an enemy surveillance device!”. Unfortunately, they were unable to really control the roaches’ movement.
Oh, this idea also pops up in The Fifth Element. The bad guys use a bugged roach. It is seen and squashed.