Crisps and even chocolate are some of the foods being given to the deer in Dublin's Phoenix Park.
Rangers are urging you not to feed or take selfies with the animals while out on their Christmas walks.
More than 500 wild deer roam the Phoenix Park.
People in the park are being told to keep 50 metres away.
Instead of feeding and taking pictures with the deer - post boxes for children to drop off their letters to Rudolf have been installed.
