TSViewer does connect to your server via the TCP query port (default is 10011) everytime when someone wants to see your TSViewer and also when TSViewer does its DB scan to collect informations for the site features for you.
This process needs only a part of a second but can become annoying. Thats why TeamSpeak Systems included a possibility to hide "ServerQuery clients" (since TS3 client 3.0.3 hidden by default).
How it worksRequirement: The server has to be in your bookmarks
1. Open the bookmarks and select the respective server
2. Click in the bottom left on "More" button to display more options
3. Remove the check mark at "Show ServerQuery Clients" in the bottom right
4. Save this change with "Apply" or "OK"