I’ve, tried garlic (Powdered and crushed), chilli powder, Cayenne pepper, egg shells, loft insulation!, powdered bay leaf all to no avail. I’ve even picked them up and put them in my compost bin. I’m now going to try watered vinegar (Thanks @gailcalled ) , if that fails, soapy water (Thanks @FiRE_MaN ). I’m going to get some pistachio shells or stones (Thanks @mammal ). I wouldn’t discount the prospect of eating them ( not going to though) because they only seem to eat what we would (Thanks@Yarnlady),I not French! And thanks to all other contributors
Anyway, the hamstrung battle continues.
p.s Well done you French for your gastronomic adventurousness.