Nautilus window opens after device usb connection. But this is not a storage device. It's even not mounted. It just takes some power supply via USB. How to disable automatic window opening after not mounting?
Bring up a terminal window, then install
sudo apt-get install dconf-editor && dconf-editor
org > gnome > desktop > media-handling, uncheck automount-open option on the key list.
No need to install anything, simply run following command.
gsettings set org.gnome.desktop.media-handling automount-open false