We live in eastern St Louis County and are accustomed to large hatches of blackflies (Simulium & related) in May; however, in the last week swarms of what I thought were 'friendly flies', large fuzzy non-biting types. appeared. Except that they apparently do bite. Normally the deer flies don't hatch until at least early June, but these don't look like our usual deer flies. Curious what they are, why they are hatching now, and is this a climate change symptom or something else? I hope the attached are sufficient for an ID.