Any idea what is biting us?

My family and I have recently been experiencing some type of bites. It resembles flea bites in behavior. But we have had fleas before and we could see them. We've checked our dog and around the house- no sign of fleas. My husband and I don't have bite marks but we can feel them and they itch. My daughter has little red bite marks but they don't seem to itch or bother her. We experience the bites sleeping, walking, and sitting. We've had the house checked for bed bugs and that's not it. Whatever is biting us we can't see them. Any idea what it could be and how to get rid of whatever it is? Thanks!