During the plague of the 5th trumpet when horse-sized armor-plated locusts swarm out of the Earth it's said that they won't hurt those who have the seal of God on their foreheads.
5/7 Seal of God
November 8th
The fifth trumpet/vial involves an army of horse-sized armor-plated locusts which are probably at least as terrifying as the Xenomorphs in the Alien franchise.