Which bite leads to the formation of vesicles and pustules?

The formation of vesicles and pustules is characteristic of a fire ant bite. Fire ants inject venom that can cause a localized inflammatory response, which leads to the development of painful pustules that can later form vesicles. This is due to the cytotoxic properties of the venom, which can induce a significant immune response and results in the skin forming blisters filled with fluid.

In contrast, bites from a black widow spider typically present with systemic symptoms such as muscle cramping and pain due to neurotoxic venom, but not with vesicles or pustules. A bite from a brown recluse spider often causes necrosis at the bite site, presenting as an ulcer or eschar rather than vesicle formation. Scorpion stings can cause various symptoms depending on the species, but they usually do not lead to the specific formation of vesicles and pustules like those seen with fire ant bites.

Therefore, the correct answer directly correlates with the symptoms specifically associated with fire ant bites, emphasizing the unique pathological response these bites elicit.