It is only the male Pale Prominent which has the twin tails and, given that the tip of a moth's body is where the action takes place in breeding terms, I guess they must serve some purpose related to sexual attraction. Note, though, that the moth is nicely proportionate, with equally long palps, organs primarily designed for testing whether material is edible.
|Update: this is the dark (combusta) version of the Clouded-bordered Brindle - many thanks to Dave Wilton of Upper Thames Moths|
Here are some of last night's other visitors, which I have yet to identify apart from the dark-n-light couple of Heart and Darts and the Common Wainscot at the bottom. It was a busier evening than most have been recently, probably because of warmer temperatures. Update: I have taken my courage in both hands and put my best shot at IDs in the captions. Endorsement or ridicule equally welcome.