Dead mice don't tend to smell they are very small and quickly consumed by insects or become totally desiccated. I'd guess if it's mouse related they have a nest inside the wall and the smell is of their excrement and urine absorbed into what every they are using as nesting material. It will go away once they clear out of the nest and it dries out. Keep putting out the poison but use more than one type, they tend to learn what they can and can't eat in short order.

A smell doesn't have a sound, so I can't be sure, but maybe it's a dead animal somewhere.

We had mice in our attic. We heard noises in the night and stuff had been nibbled. After catching 3 in the traps, we haven't seen or heard any activity in our attic so we think they are all dead, We had also put poison down.

The problem is, about 2 weeks ago I noticed a slight odour in the room I share with my sister, it smelled kind of like smelly shoes so my first thought was that my old scruffy Ugg boots were causing the smell so I got rid of them. However the smell remained. My sister and I changed the bedding and put any dirty washing lying around the room in the wash, we got rid of anything we thought could be causing the smell. Our Mum helped us search the entire room for the source of the smell, we turned the room upside down, emptied drawers and wardrobes. We found NOTHING, the only conclusion we can come to is that a mouse ingested poison then died in the wall cavity or in the ceiling above the room. You can only really smell the odour near the door so we think it is in the wall around there. The smell isn't awful, it is bearable, it is hard to describe but it smells like a mixture of damp (like the way dead grass smells when it is wet and decaying) and like I said old smelly shoes. Does anyone know what a dead mouse smells like? The smell is making me paranoid as I don't know what it is and I don't want to have friends over.