Hedgehogs eat slugs, snails, insects and worms. They are not only insectivorous they also are omnivorous and will eat dog food, cheese, biscuits, currants and sultanas. Many but not all will hibernate in Winter. Do not give them milk and salty food. Replace meaty food every day. Ensure they can find a source of water.
I wonder if they eat Christmas pudd? More likely a little finely chopped turkey. I suppose they might be asleep? Please someone tell me!