Just as I caught focus on the flying thing, I realized it was not 1, but 2 flies who had literally slammed into each other in mid flight, one was belly down, the other was underneath it and was belly up and they were copulating! They were flying without making sense of any sort of flight pattern at all, as they were connected by their posterior sex organs and the male was depositing it's sperm into the female's spermatheca (that has a nice ring to it, better than vagina). The female controlled the flight for several minutes and then suddenly brought them both down into the sandbox sand. From there, while the male was still making it's deposit, she triumphantly dug a hole in the sand and they both slipped into it, not to be seen again.
Here's a doodle for you that I just quickly did, to enable you to grasp the image better
(colors and size not totally representative of actual flies).
It was completely fascinating. I couldn't take my eyes off it. Better than watching dragonflies mate, though I have to give credit to the totally flexible male dragonfly.
Facts about copulating flies:
- Female flies are monogamous because they only mate once in their life span.
- Females can lay their eggs in several batches of up to 150 eggs at a time, sometimes reaching up to 1000 eggs in her egg laying period.
- She will begin laying her batches of eggs within 3 or 4 days of copulation.
- Flies take 12 hours to become pupae (which resembles tiny maggots) and are fully developed within 5 or 6 days.
- Newly hatched flies have their procreation junk fully developed and can begin reproducing immediately, no waiting for the penis to grow or balls to drop.