It isn't just us they'd consume. Any organic
matter at all would be stripped from the land
surrounding their nest and brought back there.
Even sufficiently fertile soil would be siphoned
from the ground, causing a spreading desert of
sorts to surround their nest. Alongside consuming it,
it's thought that these beings were fully capable
of reconstructing this organic matter into new
dolls who could then themselves grow by doing
the same. It would explain their frightening
numbers and even more worrying increase thereof.