Hi
Just wanted to share a wonderful image taken a while ago whilst exploring WW2 Pillboxes of the beaten track. Many i have come across house Butterflys usually attached to the ceilings and inner walls, most are of the Peacock variety and they seem to produce a very audible almost hissing noise when you first enter their shelter.
Yes, I remember when I was a kid, I was rooting around our garden shed and was frightened out of my skin by a loud hissing noise. I had no idea what it was and actually thought it was a snake. I was amazed to discover it was a peacock butterfly! I have never heard one make that noise since, but I suspect it only happens when they are disturbed whilst trying to hibernate? As the noise is made at the same time as the wings open, it seems obvious how effective a tactic this could be to ward off a predator. The butterfly in your picture is also holding its antennae close together and slightly backwards in a strange pose - I suspect the wings actually cover the antennae up when they are asleep for the winter to prevent them being damaged?
With Peacock Butterflies, the butterfly makes the noise with the brown hairs on the top of its uperside, near its head. When its attacked by something like a bird, it rubs these hairs and flashes it wings. It might look like or remind a bird of a cat or something to a bird, and a cat is a birds predator after all
Thanks for the post, Eagleday. Checking out WWII pill boxes for butterflies is something I had never considered doing but as there are plenty around here I might do it.