Hello! Approx. how much time spiders, worms etc. spend on a web site each visit? I assume- its a matter of few seconds, if not less... Why I care about it? Because, in AWStats, one can find visit duration statistics. Therefore, if non-human trafic only spend that much time each visit, it could be an indication of how much time HUMANS spend on the site.
I have 100K pages and a spider can spend hours poking around.
Some scapers/spiders only hit a page or two and run away, others try to take hundreds or thousands of pages at a time.
The only real conclusions you can draw that it's not human if it takes too many pages too quickly, downloads way more pages than a human can read, or stays on your site for a very long extended period of time.