As a DM dice are there to make noise behind the screen and raise tension. They're a psychological tool as much as they are a randomizer.

Personally I play a lot of World of Darkness games, which runs on dice pools, so if I can just keep obviously adding more and more dice to a pool, recount once or twice and roll to really sell the illusion that they may be in for something a lot bigger and scarier than they are. Or just roll a handful of dice as moments are going on, give a facial reaction and let that simmer under the surface for a while.