It's a little misleading to say that volcanic forces pushed the rock into the air - when the plug was formed, the air around it was a volcano. The plug would have been a lava vent, which cooled into a chunk of basalt. As millennia ticked by, the softer rock of the volcano (sandstone, at a guess) eroded away and left the harder basalt standing alone.

Forgot to mention that they had a spider wrangler to handle the tarantulas. SPIDER WRANGLER! Wow.

Actually the trick with putting a female spider in to make the male spiders active was deliberate and known about beforehand. Alfred Molina discusses it in one of the bonus features on the DVD.

Is there really any competition against Japan in pure strangeness? They really do seem to be above and beyond everyone else. Example: these girls, creepy.