It is important to state here — though evidence will be considered in detail later on — that all three women have either had "dreams" or normal recollections of having been shown, at later times, tiny offspring whose appearance suggests they are something other than completely human... that they are in fact hybrids, partly human and partly what we must call, for want of a better term, alien. It is unthinkable and unbelievable — yet the evidence points in that direction. An ongoing and systematic breeding experiment must be considered one of the central purposes of UFO abductions.
p. 130 - Intruders: The Incredible Visitations at Copley Woods (1987)