A chilling wind whips through the hollow. Winter's bite grips your spine. The very air you breath stings. Snow swirls all around you, yet, the trees... the trees are motionless in the gale, unaffected by the cold, biting winds.
The PCs discover a large white ball in the branches of a tree, or in a niche in a cave. Unless magically examined, or by a PC with a specialty in insects, it is a plain, smooth white ball. After a short time, it hatches and releases hundreds of spiders, cockroaches, some other nasty bug