It is not uncommon to come across habitats, systems, or even whole regions of space in the Fringes that are convinced that there are unknown xenosophonts out there. In such situations, the believers fall into one or more of several generic types - or stereotypes, if you prefer:
1) Those who would greet the new xenosophonts as potential friends 2) ...as potential resources or 3) ...as potential threats
There is a fourth general grouping as well - once that believes that a given area is under the control of unknown entities. Sometimes, this is a correct perception - as in some of the less baselinophilic virches manipulated by near-blight intellects or in the case of God Dwellers or certain brazen Hider clades. However, in many other recorded cases, there are no detectable intellects within the region(s) in question.
What is of particular interest to many baseline psychographers/memetic researchers is the similarities amongst some of these claims across broad swaths of space. In clades that have no apparent linkage since the Nanoswarms and Great Expulsion from Earth, there have been recorded up to 40% comparison of at least three types:
a] the "tentacles" - intelligently-acting tentacular devices often springing from native soil or (rarely) rock. These are often noted for their violent response to physical interaction. Traditionally, there are no detectable changes in the soil structure where a tentacle has been noticed, except occasionally from physical violence against sophonts and/or their tools in the area.
b] the "lights" - glowing objects often of small diameter (<.1m) but occasionally of planetary scale which appear to observe, track or otherwise non-invasively perceive baselines, baseline activities, and/or baseline technology. There have been many 'successful' data capture events where baselines were allegedly able to garner data on such things, but invariably these records are either discovered to be forgeries, technical aberrations, or are corrupted. (Of course, some baselines see this as a sinister plot of some sort...) These phenomena have been called 'Foo' or 'Yufoes' in various regions since early times.
c] finally, only a few baseline communities have had encounters with 'shifters' - bipedal beings that are capable of swiftly changing personas and physical identification, often at a level capable of foiling non-invasive nanotechnical sensors. There have been high-carbon leavings of some of these devices, as they appear to have some sort of self-destruct method which renders them into a graphite slurry with little if any resultant recoverable parts.
Note: both the Institute of Xenoscience on Eden and the Board of the Encyclopaedia Galactica on Ken Ferjik currently reject the possibility of hidden xenosophonts within the Terragen Sphere. However the Zetetic Institute of Phenomena Investigation in orbit around Millennium in the Terran Federation has suggested some possible scenarios for the continued persistence of these legends of undiscovered xenosophonts in the very heart of human space. Once human derived civilisation encountered true xenosophonts in the third millennium and found them to be nothing like the legendary aliens of old, belief in the yufoes and shapeshifting aliens declined, but did not disappear entirely.
Belief in hidden aliens has a long history, dating back to the Industrial age of Earth; this may be the reason for the perceived similarities between the legends. Another reason might be shared unconscious imagery, inherited by human derived clades all over the Orion Arm. It is notable that xenosophont legends are markedly different among provolves and vecs compared to those found in human derived species. The Zetetic Institute has mapped such psychological imagery in the deep structure of baseline human brains and of several derived clades, and reports that not all the legends have psychological origins.
According to the Zetetics, if xenosophonts are hidden among the stars and worlds of the Orion Arm, then they must either have technology far in advance of the archailects, who presumably would be able to detect widespread xenosophont activity, or they have already been detected and are known to the archailects. One possibility rejected even by most authorities in the open-minded Institute is that contact has been secretly maintained since the early Information Age, when several mythical sightings of xeno craft were supposedly made on Earth.
One minority view notes the bizarre and inconsistent behavior of these legendary xenos, and suggests that they represent a post-intelligent relic of some earlier species, perhaps the Auld Limners or the Thyresta. Such a vanished civilisation could have evolved into one or more species in which sophonce has atrophied and now is only sufficient to enable the creatures to hide efficiently and operate their autonomous and self-repairing technology.