If you think you've spotted a robot in your web server logs, you can use these tools to lookup the IP address, which gives you a clue as to who may be operating the robot.
This form looks up the IP address in the internet number allocation registry to see who owns the IP address block for the address. This is usually a company that operates a robot, such as Google, or an Internet Service Provider (ISP) used by the organisation or person operating the robot. But remember that sometimes robots are run from compromised computers, without the knowledge of their owners.
Alternative you can use these external lookup services: