Blunt force is a non-elemental hazard in the Pikmin series, consisted of two physical forces: crushing and stabbing. Rock Pikmin can withstand blunt force attacks, although Winged Pikmin are also mostly immune to being crushed.
Pikmin have weak bodies that cannot resist most forms of crushing forces, except for Rock Pikmin. Once a Pikmin is crushed, it becomes flat in whatever direction it was crushed, then disappears with a spirit, with no way to save it. However, Rock Pikmin merely become partially buried in the ground and unharmed, and must be left to unearth themselves automatically after some seconds. The time it takes for them to unearth does not depend on their maturity and is random between six and eleven seconds.
Leaders are not immune to crushing either. If a leader is crushed, they will become flat for a second, and slowly return to their original size. Being crushed normally causes considerable damage, and the prolonged damage animation may allow the leader to be hit by a different attack while they are unable to react.
In Pikmin and Pikmin 2, crushing can be identified by the distinct sound Pikmin make when killed. In Pikmin 3, any attack that a Rock Pikmin can survive by becoming buried counts as a crushing attack.
Ways to get crushed
Although the Mamuta crushes Pikmin into the ground with its hands, this does not count as a crushing hazard, as this is actually beneficial to the Pikmin. It's still harmful to leaders, however. In addition, the Quaggled Mireclops has some attacks that trample Pikmin, killing them in the process, but this is a fatal attack that not even Rock Pikmin can survive.
Stabbing is a force similar to crushing, in that Rock Pikmin are immune to it. Whereas most Pikmin would get skewered, Rock Pikmin are simply knocked back from stabbing attacks.
The following enemies have stabbing attacks that Rock Pikmin are immune to:
In the same vein as the Joustmites, it is assumed that Cloaking Burrow-nits in Pikmin 2 also have an attack that counts as a "stabbing" hazard, although this force is not distinctly recognized as being a hazard by any game mechanic or explanation.
The rough exterior of Rock Pikmin gives them the ability to survive blunt force attacks, making them quite valuable when fighting enemies that pose a crushing or stabbing hazard. However, Rock Pikmin won't completely ignore blunt force attacks like other Pikmin types ignore attacks of the hazard they are invulnerable to: crushing attacks temporarily and partially bury them, and stabbing attacks knock them down. Because Rock Pikmin have such a solid body, their attacks could almost be considered blunt force in and of themselves. When attacking enemies, they do not latch on and pummel, but rather cause damage solely with the impact. This even has a special effect on some enemies, like instantly grounding minor flying enemies such as Swooping Snitchbugs, or instantly crushing Skutterchucks (whereas other Pikmin types will simply latch onto the Skutterchuck if it's vulnerable, and take more time to kill it).
There is a glitch in the first two Pikmin games where an enemy or a certain object will crush a Pikmin abnormally, when it isn't even meant to crush in the first place. Very rarely, an object on top of a Pikmin will make said Pikmin vanish.
Yellow Wollywog corpse crushing
As seen in a trailer for Pikmin, it appears that in a development version of the game, Yellow Wollywogs could crush Captain Olimar's army during their death animation, where they tense up and fall to the side. In the final game, this does not happen, except unintentionally, with the aforementioned glitch.