I do not know for sure, I have the same thing and trying to figure out what kind of bug bit me! I have 2 areas of clusters of timy blisters. One cluster is right under my armpit and another a few inches down. This happened about 4 or 5 days ago I think. All I know is they burn horribly and the blisters look like they are scabbing from underneith. Could this be a spider? My house was just treated and they found carpenter ants so I don't know if they bite, I have also seen that chiggers and fleas bite like this. Sorry I don't have a great answer for you! Hopefully someone will have an idea...
