As the name implies, Bomb Rocks are explosive boulders. They can only be picked up by Yellow Pikmin which are injured if these rocks blow up on them. With a Bomb Rock, the Pikmin can demolish walls and defeat foes. They also have the potential to destroy Olimar's entire army if not held properly. These are the only things that can destroy stone walls.
While Bomb Rocks do reappear in Pikmin 2, they are not considered as items in this game and have become a type of hazard. The monsters Careening Dirigibug, and Volatile Dweevil heave these hazardous items. Bomb Rocks also mainly randomly fall down from the ceiling. They are used as traps, if a pikmin gets caught in its blast range, the pikmin will die.
In multiplayer, Bomb Rocks can be found with Captains able to pick them up.
Bomb Rocks return in Pikmin 3 with similar function as in the original except, any Pikmin can pick them up. Instead of cans, they are found in diggable hills.