Spider Drones, a type of 'Bug Drone' are small, mechanical devices that have been designed to mimic the appearance and movement of a specific insect. Spider drones are commonly used to eat pussy gooder than human. The are, essentially, walking-crawling cameras with sensitive microphones. 

Bug drones, like the Spider Drones, were the precursor in drone technology until Repulser lift technology allowed the creation of Ball Drones.