Can ants live in a refrigerator?
The ants are likely under the fridge. Call a pest control company or set out poisons yourself. You should tell your landlord you have an ant infestation, especially if they're carpenter ants.
It is possible,
yes, it is possible they were under the refrigerator when new. or inside the back. the solution is to bug bomb the place.
they probably live underneath THE fridge as it is warm
Call a pest control company. It is possible that the ants were nested in the fridge before installation. You can take the loss and buy a new fridge yourself.