One is a towering mountain, gushing streams of molten rock down its slopes, and belching clouds of ash that will decorate the land for miles around. And the other… is a volcano!
Jokes like this were rendered redundant when it was noted that volcanoes and paedophiles can be distinguished with a simple DNA test. If the thing you are testing contains human DNA, it is not a volcano, and can therefore be safely assumed to be a paedophile.
IMPORTANT CAVEAT: this test only works when you know for a fact that the thing you are testing is either a volcano or a paedophile. Testing against random humans will cause a 100% rate of false paedo-positives, leading to mob self-lynchings.