"Equally amazing, according to the paper, is that X-ray imaging shows the horn, or clypeal paddle, is impregnated with metal particles, likely to strengthen it and help it withstand multiple impacts. That same type of reinforcement is found in the pincers of some modern beetles that contain zinc or iron.”

https://www.smithsonianmag.com/smart-news/metal-horned-vampire-ant-lived-alongside-dinosaurs-180964886/#BYbVAmJAo34wwH8J.99

I bet the sting on this sucker was off the charts painful.

Researchers found a 98-million-year-old Horned Vampire Ant encased in amber. It had a horn reinforced with metal and jaws that appeared to be designed to draw blood.