RDS: ReadIOPS spike due to activity in rdsadmin database

Last week I've noticed a sudden spike in the ReadIOPS activity across all our RDS instances. It happened in two batches, actually, but it affected all of them:

Digging into this with the Performance Insights monitoring panel I can tell these spikes correlate with activity on a database called rdsadmin that seems to be present on every RDS instance:

And if I look at the SQL section I see this query being executed at the moment:

SELECT DATNAME,
	LARGEST_DB_BYTES,
	ALL_DB_BYTES,
	OLDEST_XACT_SEC,
	OLDEST_XACT_XID
FROM (
SELECT DATNAME,
	DATALLOWCONN,
	CONNECTIONS,
	BYTES,
	MAX(BYTES) OVER () LARGEST_DB_BYTES,
	SUM(BYTES) OVER () ALL_DB_BYTES,
	MAX(SEC) OVER () OLDEST_XACT_SEC,
	MAX(XID) OVER () OLDEST_XACT_XID
FROM (
SELECT D.DATNAME,
	D.DATALLOWCONN,
	PG_CATALOG.PG_DATABASE_SIZE(D.OID) BYTES,
	SUBQ_DB_BY_ACTIVITY.CONNECTIONS,
	SUBQ_DB_BY_ACTIVITY.SEC,
	SUBQ_DB_BY_ACTIVITY.XID
FROM (
SELECT A.DATID,
	COUNT(*) CONNECTIONS,
	MAX(EXTRACT(EPO...

Does someone know what this query is about and why it triggers across every RDS instance? Does it depend on activity on other databases or is it a RDS scheduled maintenance task? If so, is there a way we can anticipate/delay these spikes so they don't potentially affect our databases' performnace?