On a brand new, unused Postgres managed database cluster, why are there tons of connect/disconnect events appearing in the logs?

These logs appear in the ‘Recent logs’ section of the ‘Logs & Queries’ tab on the control panel for the managed database I’ve just created. There are several every minute. The database cluster is configured to only accept connections from an Ubuntu Droplet, which has also just been created, and is not doing anything. What causes these logs? Does it indicate a problem? Is there anything I can do to stop them or filter them out? Here are some examples of what I mean:

06-16-2019 01:23:21PM	postgresql-11.service	[11-1] user=postgres,db=defaultdb,app=do-stats,client=[local] LOG: disconnection: session time: 0:00:00.044 user=postgres database=defaultdb host=[local]
06-16-2019 01:23:21PM	postgresql-11.service	[10-1] user=postgres,db=defaultdb,app=[unknown],client=[local] LOG: connection authorized: user=postgres database=defaultdb
06-16-2019 01:23:21PM	postgresql-11.service	[9-1] user=[unknown],db=[unknown],app=[unknown],client=[local] LOG: connection received: host=[local]