Factual error: A meteorite falls onto Munson's bed, setting fire to it. He covers it up with blankets. But the meteorite is still red hot and would surely burn through, and set fire to his bed again.
Factual error: A meteorite zooming through the atmosphere would crash on the ground at a high speed and with a really high temperature, not like a cardboard orange-painted ball thrown from a couple meters away, as it happens in the movie.
Answer: Since one meaning of "bore" has to due with digging tunnels and they are used in the torture scene, one can assume that they are worms that eat holes into your flesh.