First you may have a whole in the roof you may have mold and dogs can sense smells and will alert you to hazardous smells. There can also be rats, mice or animals that have gotten access through the roof and gained access inside the walls. If that is the case don't leave food lying around the house and go up in the attic and put mouse traps up there. You will also be able to visually inspect up there by just popping the hatch and peaking in with a flashlight to see if there are any nests. This may solve your problem. If not, this is another option to rule out. First of all exterminators can't do much. They do a visual inspection of the corners of the house to see if there is feces from termites then they have an idea if there are termites in the walls. The only way to know for sure is to remove a small piece of the sheetrock where bernie is looking up at. Then you will know if there are termites. It's a simple and inexpensive process and the workers at Lowes or Home Depot will be happy to explain to you. Make sure you get the landlords approval first. I don't think the landlord will be too thrilled but if there are termites he's going to want to get them out asap because the job will cost him much more in the future if he delays.