It was faint at first. I’d catch a whiff of something truly off-putting, however then it would fade. I thought there may have been something stuck in the garbage disposal. I kept splitting up lemons & putting them down the disposal thinking it would do the trick. It didn’t. I was lighting scented candles & leaving windows open, to no avail. I simply couldn’t figure out where the odor was coming from. It was stronger in some rooms than others however it was spreading throughout the house. When I noticed the cat pawing at an air vent, the light popped on over our head. I got on our hands & knees for a close sniff at the vents. That’s when I knew something had died in the air duct, judging from the cat’s reaction to the odor, I figured it was a mouse, but knowing there was a dead pet in our heating & cooling ducts was a frightening thought. I had to get the little guy removed & whatever parts of our Heating & Air Conditioning system it had touched, thoroughly cleaned. Some Heating & Air Conditioning companies told me to call pet control first to remove the mouse. I didn’t have the patience for that. I finally found an Heating & Air Conditioning professional who agreed to remove the rodent. Turns out it was an unfortunate chipmunk that caused the foul odor the air handler had spread throughout our home. The Heating & Air Conditioning professional removed the carcass, cleaned the area of air duct where the chipmunk died & changed out the filter for the oil furnace & air conditioner. He ran a check on the entire heating & cooling system then recommended I consider adding an media UV air purifier to help with cat dander. I decided to go for it. I only want scrub air inside our new home from now on.