Beyond the simple fact that I know these are flies, I'm just not sure of their exact identity. But while species and genus and family of these members of the insect order Diptera remain a mystery—honing my fly ID skills is an item on my taxonomic bucket list—what they're doing on this sunny but cool afternoon is pretty darn obvious. Why they've chosen to court and mate on the leaves of a Winter Aconite is anybody's guess, but the urge took a bunch of these flies and, while I moved in for a prurient close-up—naturalists are forever moving in for prurient closeups—several couples had the same behavioral idea and rested in tandem. Ah spring!