caterpillars?

Hi all,
I've just been to water my pots & noticed one pot with nast.'s in them had a 'munchy' bit out of one leaf. I turned the leaf over (something i've learned to do since being on here - thank you ) and there were about 5 or six tiny caterpillars on there.

They are really small and are grey sort of colour with black heads - too small for me to photograph, it just wouldn't come out with me taking it.

Any ideas what they are please? I know it's not good if they're eating my plant, but I have loads of these so am not bothered if I'm helping some butterflies. Not so sure if they're moths though:eek: So what do you think, should I kill them & if so how - no touching please:rolleyes:, or can I leave them?

Thanks

 

Hi
Have these every year on my Golden Creeping Jenny (Lysimachia nummularia 'Aurea'), but never see them on ant other plants.
The first year it happened they stripped the leaves off to the stems, before I discovered them.
Every year since I watch out for them and a quick spray with an insecticide get rid of them overnight.
They are the caterpillars of a little moth!

cheers