proboscis

We weren’t quite sure what attracted this Aglais io—Peacock butterfly a member of the anglewing tribe, see previously here and here, to our windowsill long enough to photograph (click to magnify) but this individual probed around for quite a few moments before flitting away, tolerating our curiosity on the other side of the glass pane. The eyespots are the most obvious defensive mechanisms for passerine predators—also see above—but they also apparently emit a hissing sound that deters hunters.