So as the title implies, the mining drill head will currently explode if you click it once without it being anchored. This includes misclicks as you're loading and unloading it from the mining train or trying to drag it.
I feel like it should have a random number between 2-5 clicks before it explodes at least. I don't know how many times I've tried to drag it and wound up blowing a hole in the wall near me and getting loaded with shrapnel.