Fridge making peculiar tumult? It is a timed sound and it sounds close to a grinding...

It is a timed sound and it sounds close to a grinding or rattling. It doesn't own an ice contrivance. The sound only just recently started. and is really irritating and seem to be located at the back of the fridge at the top. I'm associating it next to the thermostat but it doesn't always come on surrounded by regular intravels so really unsure.
Need warning on identify carpenter ants and the...
Answers:    HI, You have fan that go on at timed intervals within the freezer compartment. I do not know how old the fridge is,so I`am freshly guessing at the noise problem.The hanger-on bearings may be starting to wear out from every year operation.They are easy to replace by taking sour back panel in freezer com partment.You could catch parts and help at this site.{repair clinic.com}.Good Luck.
How much does heat bill cost compared to...
Ours does that when it defrost. And it is new.