While taking a shortcut back to their cave, Dino Boy and Ugh are separated by a volcanic eruption. Dino Boy ends up trapped in a avally of gigantic insects as he fends off attacks from mammoth-sized spiders and dragonflies. His troubles are only beginning however, as he soon finds himself confronted by a tribe of giant fire ants. Ugh arrives just in time, causing a raging river to flood the ants away from his young friend.