Implants are foreign objects found in some abductees' bodies.
Evidence suggests implants are inserted at various times into the abductees' bodies and removed or replaced for unknown reasons. Implants are usually attributed to Aliens, but new technology exists for human implants as tracking devices, though not yet approved for use in the United States. However, it is certainly possible that various military or security agencies around the world could be using these technology secretly. Implants come in different sizes in shape. Round implants vary in size from a tiny bead to a larger, rounder object the size of a dime.