An electric eel can jolt its prey with hundreds of volts of electricity , but if it curls up around its victim first it can double that zap, according to a new study. Researchers made the discovery by placing an eel in a tank and dangling fish wired with electrodes in the water. An eel’s electric organ, which is comprised of horizontal strands of nervous tissue running along the length of its body, generates an electric field inside the animal with the positive pole developing near the head and the negative occurring near the end of the tail, the team reports online today in Current Biology. Curling up around prey brings the two poles closer together and causes an increase in the electric field strength in between. The experiments indicate that eels use the curling tactic more when their prey continues to struggle: When scientists continued to jerk at the electrodes attached to the prey, the eel continued its curled electrical attack. The largest eels, which generate the most voltage, were less likely to need the curl tactic to stun their prey, but as this video shows, even big eels manipulate their electric field to subdue resistant prey like crayfish.