I am getting some kind of bites that itch. They last several days. Usually they have a very tiny hard bump in the middle that looks l like a blister. I can get new bites anytime of day, but they itch worse in the evening. I have checked my bed and my clothes inch by inch, especially the seams. I have found nothing. I am staying in a a cation home that had a lot of spiders when I arrived - tiny ones all the way up to daddy long legs. We have sprayed the house, then had it cleaned thoroughly. How do I stop this biting?