The abduction phenomenon is an umbrella term used to describe a number of hypotheses, claims or assertions stating that non-human creatures (usually aliens) kidnap individuals—sometimes called "abductees"—usually for medical testing or for sexual reproduction procedures. Many such encounters are described as terrifying or humiliating, but others describe them as transformative or even pleasant. Reports of the abduction phenomenon have been made from around the world, but have perhaps seen most mainstream attention in the United States.