I think the default response to system could be mount and open Removable Drives when hot-plugged.
There is a option to it, go to Settings --> Removable Drives and Midia (Hardware section) and in the Storage tab there are 2 options: Mount removable drives -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1261460 Title: When pluggin USB external drives Thunar doesn't automatically mounts them To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunar/+bug/1261460/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs