The starlings are doing you a favour and ridding you of leatherjackets
and their pupae. They munch on grass roots.

They're daddy-long-legs / crane flies. Mayflies hatch from water: aka
caddis fly, the grubs make a protective jacket of débris and carry it
about. May be of grass, reed, and twig detritus, or small pebbles and
bits of shell.

Cheers thanx for the replies.

Got my three year old putting a pinch of grass seed and filling with sand
from sand pit - there are hundreds/thousands of holes - trouble is hes a bit
heavy handed and I came home to find a lawn dotted with piles of sand (and
some seed) LOL

Why the synchronised emergence??? Did not see any this morning at all

Nik