A new spot for me and IDed by helpful Twitter users, these are Ivy Bees (Colletes hederae), a type of mining bee that first appeared in Britain in 2001.
Here’s a helpful summary of the Ivy Bee from Naturespot.
They seem to be colonising a section of my Dad’s lawn and an adjacent border. They apparently like loose soil: Sandy and south-facing by preference. They fly for about 6 weeks in the autumn, feeding almost exclusively on ivy flowers. So I guess that means it is officially autumn then! 😦
I’ve yet to tell my Dad that they nest in dense clusters, with the possibility of a very large number of nests grouped together … and that they will re-appear next year.
Happily, those scrummaging bundles of bees are mostly made up of males (with no stings) in search of an emerging female. The bees are not in the slightest bit aggressive, but they are super cute.