Leaf insect

I was sitting opposite Elf the other evening talking to her, when a strange movement caught my eye. Walking across the wide expanse of timber floor behind her, on his way somewhere, was a leaf insect. I'm sure they can fly if they want to - it's their wings that give them the leafy look isn't it? They probably walk up and down a branch or stem, safe in the knowledge that although they are moving, they still fit in well enough to get by. However this guy was strolling, as brazen as you like, his bright green-ness standing out from the brown floor like a neon sign. When I got closer I could actually hear him whistling.