This cinnabar moth (Tyria jacobaeae) is able to fly in the daytime because it is loaded with poison and nothing will eat it. It gets its name from its colour - the red is the same colour as seen in cinnabar, a mineral containing mercury sulphide. The hindwings, not seen here, are nearly all red.
I have often seen the caterpillars but rarely seen the moths. The adult moth gets its poison from its larva, which in turn ingests it from its favourite food plant, ragwort. This photo shows cinnabar moth caterpillars on ragwort last August.
Just about the only thing that eats the caterpillars is the cuckoo, which specialises in eating hairy or poisonous caterpillars. This photo of a young cuckoo eating a cinnabar moth caterpillar on ragwort is also from last August.
This illustration is from John Curtis' British Entomology Vol 5. 1840.