Myrmecocystus testaceus
Myrmecocystus testaceus is a species of honeypot ant found throughout the western United States and extreme south British Columbia. It is usually nocturnal, and nests in sand.
They can spray formic acid from their gasters to melt skin tissue. Instead of stinging and swarming, they stretch their prey by the legs until it splits or dies from bites and formic acid.