Bolt thieves are enemies in Ratchet & Clank. They are small, floating, fast robots with two arms, encountered on Batalia, Oltanis, and Kalebo III. Three are hidden throughout Batalia in a small area and will flee if Ratchet approaches, and can be shot for a large sum of bolts.
They are also responsible for setting mines on grind rails, on planet Oltanis during "Find the survivors of the blarg attack", Kalebo III during "Ride the Grind Rail", and were possibly responsible for laying the mines in the grind rail on Batalia during "Ride the grind rail" (though they were unseen). On Kalebo III they will attempt to stop Ratchet from collecting a gold bolt in a suicidal manner, by taking position on the grind rail themselves in lieu of any actual mines.