Hi I think they are Bright-line Brown-eye Ok - my book says the body can be green or light brown, food plants 'various herbaceous plants and shrubs'. They overwinter as a cocoon and emerge in June or July. The names aren't really confusing, this one has a white line and two brown spots on the wings,...
I actually prefer moths to butterflies, but then I've always been a bit odd!
On the other subject, I've only seen one Small Tortoisehell in London this year.
Hi
Your moth is Endotricha flammealis, one of the Pyralids. It has a strange way of appearing to rest on the back edge of its wings with its head in the air.