Strange object in the sky? Must be aliens!!
Strange noise in Loch Ness? Must be Nessie’s heartbeat!!
I wonder why the most outlandish and unlikely explanation (from prior probability) always becomes the obvious default one. Certainly with UFOs, the score so far is “proven mundane Terran stuff, close to 100%, proven space aliens 0%”, and that should tell us something.
As far as Loch Ness is concerned, people have been diligently scouring the loch for strange beasties for nearly a century now, using a wide variety of methods, with result “zilch”. If we stipulate the need for a gene-pool-supporting population of big animals which must come up for air every so often (assuming here that Nessie isn’t a fish, which is something that Nessie hunters seem to be largely in agreement about), that strongly suggests that there is nothing unusual to be found there.
