Emps have been known to burrow often, but initially, they should be provided with a burrow. Scorpions prey on tarantulas as well as the opposite. A Goliath birdeater tarantula and a scorpion of similar size would probably call a draw. It is debatable on whether they would even attempt to fight, though in an enclosure, they eventually would fight. I don't think anyone would actually know the answer to this unless they had enough money to loose either of the two. Goliath Birdeaters are quite expensive, and scorps nearing eight inches are rare (7 inches is the average and keep in mind, Goliaths can measure in at around 10+ [if I'm a little off, someone will correct me on the max size]), so I wouldn't recommend it either way. In captivity, if the scorp and tarantula are of similar size, the majority of the time, if neither is caught off guard and the meeting is from head on, the scorp will usually win, whether it be highly venomous or not. I have fed tarantulas to scorpions quite a number of times in the past (don't do it anymore cause I like them both now and keep them both). As a note, the tarantula for food, was never a Goliath Birdeater (too expensive), nor was the scorpion full grown and in it's burrow. Which ever one catches the other off guard, will probably win either way.