Bats are a common animal in Ontario and are native to this country. They are protected wildlife so removing them from an attic must be humane. Killing them is against the law. Bats have a baby season that occurs, depending on yearly temperatures between late May and early June. During this time they are protected so they can increase their population meaning that you actually cannot remove them from an area they are using as a nest even if it is on your property or in your attic. You must wait till the baby season is over. Bats do have rabies but most of the bats that are tested have rabies because the bats that can be tested are often sick or injured and have already gotten it. Expected numbers in the wild are far lower and are projected to be around ten percent. This does mean that a large population of bats in Ontario are indeed rabid and that getting bitten by a bat can pass that illness on to you or your pets or children so taking precautions in areas like forests is important. Bats are nocturnal so avoiding forests and fields at night is a good way to avoid them. A bat that is not rabid will have very little interest in interacting with humans or other animals unless threatened. They are insectivores and eat mostly flying insects and fruit. They do not attack humans to eat flesh or to drink blood however vampire bats are a real species and exist in some parts of Africa.
If you have a bat in your attic there are several things you will need to consider. As stated, during bat baby season you will have to leave it be. You cannot have it removed even if you are scared it will attack you. To avoid this do not go outside of the house during its waking hours which are usually late in the evening or when it returns in the early morning. If these times cannot be avoided, take precautions not to get in the way. When the baby season is over you can remove the bats. This is not something most people can do as it cannot be trapped with a live trap or chased out as it will attack you. It must be removed using a device called a one-way door. A one-way door is a device made of a black rubber-coated galvanized steel rectangle with either a gravity door or a spring-loaded door. The door is a flap that can be moved up and down from the entrance but lays flat when trying to reenter. This is a safe and humane way of removing small animals from an attic or entryway like bats, squirrels, chipmunks and other rodents or animals. They are not effective for larger animals like raccoons or skunks which require a large door that functions differently. If you are good on a roof then you can purchase a one-way door at a hardware store or online. You will have to find the entryway the bat used for ingress and then seal it off with the one-way door and galvanizes steel mesh. Using metal mesh that is not waterproof may result in the entryway rusting and weakening which would allow the bat to damage the door and get back in.