My question is whether there is an upper limit to this. We drink a lot
of coffee and I would hate for the little critters to get hyper and
stampede.
BRBR

A worm stampede! But who would wrangle them back into the compost?
More seriously, if you gave them a lot too much you might kill them, if the
case of P. Lyautey, who wrote the original stories on which "La Boheme" is
based, was correctly reported. Supposedly died of blood poisoning/systemic
gangrene after a long regime of 40 cups of coffee a day.
zemedelec