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

Reader Richard Tucker sent in this terrifying photo he snapped Wednesday along the Canal Walk near the Manchester Bridge.

• "I don't know what they are, but they seem to be enjoying themselves," he said.

My first instinct, and probably yours, was that what Tucker snapped was likely the first indication of the End of Days. The only thing to do, of course, would be to burn down the city and flee.

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.