Psssh!
The pieces of clothing still hanging around David's skin corroded into Ash.
The inner fluids from the ants was actually no different from a concentrated acid. And as it dropped to the ground. It started to sizzle, corroding the ground into mere particles.
Assuming David's skin wasn't as tempered as it was, he would have certainly melted. But even with his hard skin and muscles, his skin turned slight red like he had rashes, but that was how powerful the inner fluid was. David skin had still reacted to it.
David had used some mental energy to form a sort of forcefield, protecting his eyes and face from the liquid, as for the rest, he had confidence in his skin. That level of corrosion wasn't enough to affect him.
Boom!
The head of the insect that was in his hand shot out like an arrow as it slammed into the incoming insect, breaking its skull in the process while it screamed miserably.
Kiiiiiiiiii!