The companion cubes that Aperture science DID get thown in volcanoes but the ones WE found on the island were not.  We named them Companion Cubes because they act like a companion. So the 1,000 companion cubes that Aperture Science gave us were useless the ones WE found on the island are useful.

1: Enjoy it! Remember it dies like every living cube enjoy it before it passes on! Lifespan: 1-10 years

The good thing is no poop,pee,or food or drink! P.S. Not Comapnion Dice Companion Cube. Blame me sorry my mistake!