Aliens

Aliens is one of the entries in 5 Most Terrifying Creatures That Visit You In Your Sleep.

Entry Description
A Roper Poll published in 1992 suggested that nearly four million Americans reported experiences akin to alien abduction.

An explanation for many alien abductions can be traced back to sleep paralysis, in which the victim awakes paralyzed in the middle of the night often experiencing either a floating sensation or downward pressure accompanied by deep feelings of terror and helplessness.

Sleep paralysis may strike nearly 40 or 50 percent of all people at least once in their lifetime and one study found that those reporting abductions were smarter and no more fantasy-prone than the general population.