Complex sentence: These become workers and will assume the chore of expanding the nest--done by chewing up wood which is mixed with a starch in their saliva, to be spread the mixture with their mandibles and legs, drying into the paper that makes up the nest.
Split into simpler sentences: These become workers and will assume the chore of expanding the nest--done by chewing up wood which is mixed with a starch in their saliva. This mixture is then spread with their mandibles and legs, drying into the paper-like substance that makes up the nest.