I realize the point is moot now, but my own Google search for pain causing a fever led me to multiple answers of NO, and I know from my own medical issues that it is untrue, fever can be a rather rare response of the body to pain.
Harvester ants are the staple food source for most types of Horned Lizards or (horn toads). They provide formic acid - a necessary nutrient for horned lizards. A typical horned lizard adult may eat from 20 - 100 harvester ants a day. However, most pet stores do not supply harvester ants as feeders for horned lizards.
They also may use their front legs in order to eat larger food. They grasp their food and push it into their mouths. One American toad can eat up to 1,000 insects every day. Toads do not drink water but soak it in, absorbing moisture through their skin.