Solar prominences are cool and dense plasma in the hot corona. The so-called prominence bubbles are mysterious, dome-shaped, apparently void structures residing in the lower portions of prominences. Such bubbles are associated with various plasma instabilities, such as the Rayleigh-Taylor (RT) and Kelvin-Helmholtz (KH) instabilities. The former is manifested in plumes that are often produced at the top boundary of a bubble and intrude upward into the dense prominence material. The latter is found to be triggered by shear flows at the bubble boundaries. We present recent observations of prominence bubbles by IRIS and SDO/AIA, focusing on the diagnostic potential of RT and KH instabilities on the physical conditions of the prominence and its supporting magnetic field. We search for evidence of magnetic flux emergence as the origin of prominence bubbles. We discuss their role in mass ad magnetic flux transport in the solar atmosphere.