The hornet's life cycle is similar to that of the common wasp. They build their nests out of 'paper' made from wood strips and saliva in hollow trees, chimneys, wall cavities, holes in banks etc.
Hornets have an unwarranted fearsome reputation because of their size and their loud hum, but in spite of that they are relatively docile and will rarely sting. If you are unlucky and are stung by a hornet, you will know about it!