In suburban and rural areas of sunny .fr, rubbish disposal organisations
give away or heavily subsidise compost bins. This is a matter of pure
economics, but I'd like to know in quantitative terms what happens to the
waste. Everyone knows that it takes a lot of green stuff to make a little
bit of compost; if you don't have much garden waste, the bin takes years to
fill up.

Bins used to have open tops, but now they all have lids. Ours are at the
bottom of the garden, which backs onto a wood. We alternate houshold and
garden waste, including some twiggy stuff.

If you keep the lid down, there are millions of irritating fruit flies that
never seem to come out. I also find large numbers of woodlice, and the
occasional four-legged scavenger or resident.

I'd like to know what is the lifecycle of the insects; do any get eaten by
birds or voles, or do they just recycle themselves in the bin as organic
waste. A more global question is the proportion of waste that ends up as
methane and carbon dioxide.

Perhaps the ventilation holes in current designs are a bit too small, though
enlarging them would lead to more loss of water.

Does anyone know of a scientific study that's relevant to the usual
situation where you add a small amount of stuff regularly over a long-ish
period?