A headscratcher, to be sure--and apparently a brand-new one, since G### search turns up absolutely nothing.
IP to date:
83.147.153.abc (digiweb)
151.0.173.abc (apparently public wifi in Italy)
UA: Mozilla/5.0 (compatible; Greebo's Ghost; +https://www.avma.org)
Yes,
that AVMA; I checked. This is awfully unnerving, since Greebo is the name of my adult cat, who is alive and well and sleeping on my laundry.
Two visits so far.
On the 19th, from 83.blahblah: repeated requests for robots.txt and then favicon giving robots.txt as referer (i.e. more like what you'd see from a human), all to HTTP resulting in redirect for favicon (I don't canonicalize robots.txt) which was followed only twice out of 4 or 5 total.
On the 22nd, from 151.blahblah: one round of the same (robots.txt, favicon, redirect) followed by root, redirected to HTTPS; after which there were a further half-dozen or so page requests, with appropriate referer, with all supporting files including piwik; and then winding up with a final robots.txt-favicon-redirect trio.
This second day's visit was fully and plausibly humanoid, requesting a series of pages that do in fact link to each other, all in the same directory. If I hadn't double-checked the UA in logs, I wouldn't even have noticed all that earlier business with robots.txt.
Puzzling.
