It went away after 6 months. We now have a strong dead rat smell in the basement bedroom across from the bathroom. Our basement is dry? What should we do?We need help in trying to figure out this bad odour. We are on city sewer. We built house 10yrs ago. Any suggestions?

First, pour or run a gallon (4L) of water into every drain in the house to make sure it's not sewer gas from a trap that has dried from evaporation.

Next, double check for discoloration/wet spots on the walls and ceiling of that bedroom. Odors are normally associated with moisture of some type.

While you're checking for moisture, see if you can determine where the odor is strongest.

Other places to check can also include ductwork, understairs cubby's, and the exterior.