I am always a little wary of social insects, but these were so occupied by whatever important wasp business they were engaged in that they took no notice of us peering down the hole (not too closely though) and taking photos.
These Common Wasps and their very close relative the German Wasps have been introduced to Australia, where they are considered a dangerous pest species. People are frightened of them because they are attracted to food and drink outdoors and can be accidentally swallowed, resulting in people being stung inside the throat, causing swelling that can be life threatening. Beekeepers don't like them much either, as they can invade hives to rob them.
I've noticed that Common Wasps seem to be particularly attracted to raw fish, and market fish stalls can be inundated during the late summer.
In their place social wasps provide a significant natural clean up service, eating dead insects and in their turn, the larvae are one of the favourite foods of Honey Buzzards Pernis apivorus (Bondrée apivore).
For some hilarious wasp action from the French team at Miniscule TV, watch this (best with sound on).
*Pas folle, la guêpe, as I understand it, is a phrase used to describe a malicious person. It is literally 'not mad, the wasp', so I think the implication is that they are schemers, i.e. not mad, but bad.