What's been hiding in your oven?

The appliances we have for the basement were previously used at my inlaws. They have been sitting in storage for about 4 years now I think. I was excited to finally be able to cook because I was tired of cereal and pb&j. I turned on the oven to preheat so I could cook my frozen lasagna (I know not much better).
It started to smell funny to me. I've never used a gas oven before so I went upstairs to ask my inlaws if they would come down and see if it smelled funny to them. They said it was fine. I thought they were crazy because as soon as they went upstairs the smell became A LOT worse. I really didn't want that smell to stick to my lasagna. I turned off the oven, opened ALL the windows and cooked the lasagna in the microwave.
I told Travis about my little endeavore and he decided to investigate. He found that a mouse had been living in the drawer underneath the oven! No, the mouse was not in there but there was a ton of droppings. He cleaned it out and let it run on 500 degrees for awhile. with all the windows open.
After all that I was still paranoid to use it so I bought some heavy duty oven cleaner. It made it look almost new! the scary thing is I don't know if that smell is engraved in my head or if it still does smell but I think I smell it still when I open the oven.