Shove voles: how exactly does their eating work?

[psusi]

If every time they ate they expelled half the mass, then they could just keep cutting it in half for a very long time.  Instead they seem to eat it up and it's gone before long.  What is the missing trick that allows this?  Is there some minimum mass that they will eat and just void instead of expelling?

[caffeinated21]

There’s a double halving: they expel half. And then mining the tile cuts it in half again. They eat a lot, so 75% of a ton is still a ton

[psusi]

1 hour ago, caffeinated21 said:

There’s a double halving: they expel half. And then mining the tile cuts it in half again. They eat a lot, so 75% of a ton is still a ton

Yes, but how do you end up with none?  A quarter of even 1 kg is still 250g.

[caffeinated21]

Maybe they don’t excrete until they’ve eaten a certain amount?