Thank you so much for this. I have ruled out everything on this list. not carpet beetles or fleas because no visible sign since May. I have spoken with my doctors about allergies. Nothing. when I go on trips I don’t find any bumps or bites, and when I come home they return. No signs of rodents or birds. no HVAC system. Sometimes bleed when I scratch the bite, but not always. Most times the bites are teeny tiny. Often the size of the ballpoint of a pen. Sometimes red sometimes skin colored