Yesterday At Work In A Field With High Grass I

Yesterday at work in a field with high grass I felt a stinging burning sensation on my chin, I looked thinking it was an ant but found nothing. Then again on the back of my calf & once more right above my knee. When I dropped my pants all I found on the outside of my boxers was a little winged ant, but am not sure if it had just landed on me or not. But they were little red whelps & 24 hrs later they are swollen & the lowest one has a line about 2"-2 1/2" long what do you think?