Don't worry, Richmond's mayfly invasion is normal

But my cooler head prevailed, and I turned to the Science Museum's resident bug guru, Timshel Purdum (official title, Virginia C. Ellett director of education).

What Tucker saw — and fortuitously took a picture of — are mayflies, Purdum said.

Why it matters: "Mayfly emergence is a good thing. It means we have some healthy waterways for them in our area," she said.

• They come out annually, in a group to increase their safety, mate, lay eggs in the water and die within 24-48 hours, Purdum told Axios.
• "It's important each year it happens. You just may have not noticed it before because it takes place so quickly," she said.

Threat level: None (allegedly), but Purdum said, "They don't eat, so they won't harm us. They just have sex and die."

The big picture: "What that picture shows is an amazing natural event that, unfortunately, as we lose species diversity, is becoming more rare," Purdum said.