S1, E3: The third episode of The Great British Year shows Britain at its warmest. More sun means more food, but animals keen to have their share are arriving from foreign lands. That means fierce competition. Hunters time their arrival from Africa to feast on the huge glut of flying insects; hobbies race after dragonflies, and nightjars, revealed by thermal cameras, snare moths by night on a Dorset heath. Summer is a fickle season - one day intense UV rays force sea urchins to cover up, the next, thunderstorms bring out hordes of hungry snails!