Then, at my taking the cover off some sugar, it was exactly as though the walls hovered and then fell inward breaking into black dust as they fell.

They'll cluster over a drop of wine on the table just like an evil black flower with grey petals.
With one's body they can play tricks beyond belief.

They _laugh_ at one, hovering at a distance, waiting.

They watch one with their wicked little eyes ...

yes, I shall have to be careful about flies.
I've had a headache all day, but then in the afternoon there was a thunderstorm hovering somewhere near and there was no work to do.