We recently discovered two juvenile hedgehogs outside our office, who had either lost or been abandoned by their mother.
If you find a hedgehog in your garden during the day, there is likely to be a problem. Hedgehogs are nocturnal creatures and only venture out in the day time when hurt, disturbed or desperate for food or water. Look for signs of damage or distress and if in doubt, contact your nearest hedgehog rescue or vets for advice. A hedgehog may show no external signs of damage, but if it is very small may be too young to be in the wild on its own.
Do put down food and water in a shallow bowl / saucer - dry cat food or cat food in jelly will do, but you can also buy hedgehog specific pet food at most petstores. Do not put milk - this makes hedgehogs ill!