How should I interpret an empty User-agent? I have some custom analytics code and that code has to analyze only human traffic. I have got a working list of User-agents denoting human traffic and bot traffic, but the empty User-agent is proving to be problematic. And I am getting lots of traffic with the empty User-agent, about 10%.

Additionally, I have crafted the human traffic versus bot traffic user agent list by analyzing my current logs. As such I might be missing a lot of entries in there. Is there a well-maintained list of user agents denoting bot traffic or, the inverse, a list of user agents denoting human traffic?