It was winter underground.
The activities of many of the inhabitants of the underworld slowed down—and some slept. Those that could survive being frozen solid slept the deepest, but those that could dig themselves below the frozen ground barely slept at all. The earthworms were among those that chose to dig deep.
Annie (short for Annelida) was an earthworm and to her the whole idea of freezing solid was out of the question.