Well if 20 "guests" from the same IP range visit you, and you see the IP:s come from Yahoo, Yandex, MS, Google or whatever - you know they are not "human guests".... And usually they all use Mozilla 0.0 as their "browser"...
Google, Yahoo, MS and likes each have several identified IP class C ranges reserved for this to gather info... Maybe some yet-to-be-identified too...
As a sport, I sometimes do a search on newly posted items in the forum when I see a Googlebot or such on the site, and I usually get a first page hit when using a forum topic subject or parts thereof on the identified bot provider's search engine ...
Since I use Google Analytics, I can at least follow the Googlebot visits in time too...
As I said, it would be nice to be able to configure recognition of what you know are bots/crawlers/non-humans... 😄
He who asks a question is a fool for five minutes. He who does not ask a question remains a fool forever. [Old Chinese Proverb]