Complex sentence: It has also been seen in "Mossflower" and "The Bellmaker" That there is a form of monarchy among the squirrels, however, it seems to die out before many of the latter books.
Split into simpler sentences: It has also been seen in "Mossflower" and "The Bellmaker" that there is a form of monarchy among the squirrels. However, it seems to have died out before many of the latter books.