Children under the age of 2 years, do not need a ticket to enter the park. As soon as the child has turned 2 years, they must have a valid ticket.
Children that are under the age of 12 and has a birthday on the day they are visiting Mikkelparken, will have a free entry that day. If you plan on visiting Mikkelparken for 2 days in connection with a birthday, you buy a day-ticket for the day the child does not have their birthday.