I don’t think those have been used in combat yet...as in, they are still in the developmental stage. Feel free to correct if I’m wrong, but even if they were combat ready, what sort of weapons could they carry?
The Israelis and the US Government have used a version of the vehicle when taking out high value targets. This vehicle has the capability to linger in excess of 24 hours watching developments on the ground. The X-45 is still in development while the Predator and Global Hawk have been operational for a while. I believe that the Israeli version is called Hermes.