The Bee Bug is an electronic listening device, used repeatedly by the Pie Holers. It is a large golden-colored bee broach, with a smiling face and a long stinger. At the end of the stinger is a small microphone which transmits to a receiver in Emerson Cod's car.
The bee bug has been used twice to date. The first time was while Chuck was infiltrating Betty's Bees, looking for a murderer. This only made Ned feel more unsure of allowing the girl he loved to do potentially dangerous undercover work.
The second use was more personal. After learning that Lily Charles, the woman she had always thought of as her aunt, was actually her mother, Chuck wished to talk to her mother and ask her many questions. Ned set up a surprise for her by having Olive Snook wear the bee bug while getting Lily to talk to her, as if she (Olive) were Lily's daughter. Through an unseen means, Chuck was able to ask questions that only Olive could hear, and then relay to Lily.