In Pikmin 2 treasures that fall out of enemies will occasionally become partially embedded in the ground. If Pikmin are told to pick the treasure up, they may move around to the side buried in the ground, carrying it with only their heads protruding. When the treasure moves forward, it will be sucked down further by the force of the Pikmin pulling until the Pikmin let go and die as if they had been thrown into a void. The treasure will usually then fully surface.
It is similarly possible for treasures to become embedded in walls, particularly after having been carried by a Dweevil in a small enclosed alcove. When the treasure is removed from the beast, it remains where it was if it was partially out of the boundary of the sublevel. It can be retrieved by throwing Pikmin at the bottom, at which they will hold onto and carry the treasure, eventually freeing it.