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.
The common wild toad has much the same diet the world over. There are a few species of toads that will eat dead animals and even dog or cat food, but for the most part they eat living animals. Depending on the size of the toad the food they will eat varies. To see what small toads eat see the post entitled what do small toads eat. Most wild toads will eat everything from small spiders to large rats. This includes birds, worms, ants, lizards, slugs, snails, butterflies, crickets, centipedes, most invertebrates, and even other frogs and toads.