Sharon, I didn't see where you are from. Here where I live, that could be fire ants, a variety of small spiders, certain caterpillars such as the saddleback (whic we discovered painfully this summer. Nasty burns that last months, systemic toxins for the sensitive.). We never saw the saddle backs until many stings later.
If you are truly swelling to the size of a grapefruit, that's serious, and I'd find out what it is from, and I wear long sleeves and pants and all that now anyway. Fire ants, not much of a fashion statement.
If you are truly swelling to the size of a grapefruit, that's serious, and I'd find out what it is from, and I wear long sleeves and pants and all that now anyway. Fire ants, not much of a fashion statement.