The smell of dead mice is the scent of a corpse being consumed by bacteria. While your home may get damaged by the presence of a dead mouse in the wall it is hard for the bacteria to travel through. If there is moisture showing on the outside of the wall that can cause severe mould issues like black mould which can cause serious respiratory issues and worsen the respiratory issues in someone who already has them.
Mice urine and other dangers
Mould and fungus can break away from the wall in tiny microscopic amounts that can be inhaled and cause infections in the lungs. These infections are very hard to kill as antibiotics have been so overused in society that they are less and less effective in curing issues like inflammatory respiratory illnesses like pneumonia and strep throat. This is worsened by a mouse infestation as the feces of mice can carry Hantavirus which is an extremely dangerous viral illness that can cause a pulmonary syndrome that can lead to chills, difficulty breathing, and even nausea and vomiting. This can occur both through inhalation as well as eating infected food. So if you have mice in your home and you see a chewed bag or container of food throw it away immediately as it could be infected by rodent feces and various bacteria and viruses like the Hantavirus.
Dead mice in the walls
Dead mice in the walls and their feces are both dangerous contaminants which is why the company Warfarin discovered anticoagulants. They saw the effects of these treatments on humans as blood thinners and combined with the knowledge that mice can go up to three years without drinking water managed to create a bait that doesn’t just kill the mice but desiccate them completely, with no moister or smell left in the body it becomes safe for them to die in the walls. No mould or respiratory issues or dangers can come from it. It changed the way we treat mice and has prevented many of the dangers connected with a mouse infestation. This is an important reason to call a professional when dealing with mice as domestic treatments are not strong enough to actively desiccate them and can result in dead mice in the walls that still have moisture. This will result in them rotting and cause issues like bad smells and mould.
A professional exterminator can also find entryways that mice can enter from the outside and seal them using permanent fixtures like stainless steel vented weep vent inserts and galvanized steel wall vent covers that will stop rodents from getting into your home in the first place. This is a powerful shield against mice getting into your home as well as squirrel rats and other rodents. Sealing entryways off is one of the most effective ways a professional can do to ensure you do not get mice again next year. This is because mice are a seasonal issue coming in the spring and infesting a house from the ground up. As they breed and increase in population they will continue moving up floors in the house until even the attic is infested. Trying to resolve this yourself is difficult and nearly impossible so call a professional to get rid of them permanently.