Those cute little swallows (usually barn swallows or cliff swallows) are legally protected in Ontario, and are a threatened species due to serious declines in their populations, so it is illegal to remove their nest once it is built. After the birds leave in the fall you need to remove the nests, adn ideally change the nesting spot so they do not want to nest there again next spring.  Capture netting and falconry are very effective for deterring these birds for future years. As a protected species, you need a permit to move them and we are here to help you with that.