Folks with worm bins a favor, please?

Could one of you with a tray-style worm bin please measure the diameter of the holes on the bottom of one of the trays?

I'd like to build a small bin using steel mesh screen on the bottom of the trays, but I'm not sure what size I should get. Too big and it'll be hard to keep the castings in, too small and the worms won't be able to migrate through.

I've looked around the 'net for specifics, but that seems to be the one detail left out of worm bin plans.

Hi Monolith,
I have the worm farm type worm bin and I measured the holes.
The holes are 1/4 inch square with 3/16 inch between and 1/2 inch border.
good luck,
Chuck

Thanks Chuck, that's perfect!

You are most welcome.