On Easter I was at my cousin's house (S. Side of Denver) and she freaked when we saw a swarm of black ants on her kitchen floor near her back door. She brushed them out and closed the door.
The next day, I was shocked to see some in my kitchen (I live in Boulder, CO)!! I had the door open, but the screen door was shut. Then during work, a colleague who was working from home in Longmont, CO sent me an IM: "There are a bunch of baby black ants in my garage."
I was born and raised here and have see baby black ant swarms before outside (usually just a little pile of them along the sidewalk), but I've never heard of a coordinated Easter swarm like this year!