NAGS HEAD, N.C. (WVEC) -- Two otters at the North Carolina Aquarium on Roanoke Island got a special birthday treat from aquarium staffers!

The aquarium celebrated the third birthdays of their two male North American River otters, Finn and Banks, on Thursday.

As a special treat, staffers made the pair a cake out of fish, blackberries, carrots and other otter favorites, which was frozen into colored ice blocks.

The cake's coloration was also made with food-safe dyes.

The frozen cake also serves as what aquarium curators call an "enrichment" technique.

The otters can play with and investigate the ice blocks in order to get the food inside, while simultaneously stimulating their brains and giving them extra exercise.

For more information about the North Carolina Aquarium on Roanoke Island, click here.