IT i m writes
Hi and it could well be as I've not added any extra water to the 'mix'
;-(

Possibly too airy as well - if the stuff is too spread out in there,
it's difficult for it to stay moist.

The middle of the bottom of the dustbin was cut out (leaving a
reasonable 'rim') and is stood on plain earth. There are (now) about 10
x 20mm diameter holes around the top, just under the lid line (is that
enough / to many?). I have forked the contents about a few times but
it's sorta quite well packed in there (and never seems to fill up!g)
apart from the surface, in between the lumpy bits etc.

Do you still have the bin standing the right way up? Because the idea is
to put it upside down (so it's wider and more open at the bottom than at
the top), then put the lid on what used to be the bottom. That way, to
fork it over easily, you just lift the bin off the pile. Also, it makes
a wider base for the worms to come up from below. But the fact that it
never fills up is a good sign. Worms like unshiny torn-up cardboard,
too, mixed in with the green stuff.

--
Klara, Gatwick basin