Mice are a very frustrating infestation. They are highly social and can breed at an incredibly rapid rate. Like the Hydra of ancient Rome, you kill one mouse and two more turns up. And while we all believe wholeheartedly that we can handle this infestation on our own, we can not. We need professionals. That being said, if you want to take a wack at it here are some guidelines you can follow.
If you are dealing with rodents, it is best to call a professional mouse removal service in the Greater Toronto Area.
Start by emptying that shed, completely. Remove anything and everything that is stored in the shed and make sure you wear a face mask or a respirator, a hazmat suit would not hurt either as mice feces and urine can dry up and become airborne, putting you in danger of catching the Hantavirus. So move everything carefully and try covering everything with a plastic sheet before moving it out. All of the things in the shed will need to be sterilized before they can be touched or used again.
If you find any sort of nesting material, throw it away. If you see a mouse stomp on the ground or make a clapping noise and they will return to their hole. Mice are not aggressive at all and will never attack someone, however, when scared by something else they are willing to climb into a human’s clothing for safety. While most women hate it, children find it charming, that being said this is not Disney, do not let your child hold, touch, or feed a mouse. They will get sick. If they want a mouse, buy one from a pet store that has all its shots.
Thoroughly clean all areas of the shed, inside and out, using either a commercial-grade hospital sterilizer or with a half and half mix of bleach and hot water, boiling is preferable. You will then want to splash and mop it all over the inside of the shed. You can plug holes with steel wool that mice cannot chew through, the strands would choke them. Pack into any hole or opening you can find.
You can now perform a mouse treatment with poison or call a professional to do it and then clean all your stored items with bleach and boiling water and return everything to the mouse-free shed. If you want this done entirely by professionals you may be surprised at the cost, cleaning all of that stored stuff, moving it, cleaning the shed, its a lot of work, and can be expensive. The best thing to do is to do what you can do, safely and leave the exterminating to the exterminators.