How do you protect your AC unit. The Edmonton area has a substantial mice population and they can get into that outside condenser unit to build their nests. You’ll also find leaves and other debris, including small branches. It’s smart to clean them all away.
You should also visually inspect your unit regularly, even a quick glance as you walk by it is good practice. Chances are, you will notice something that seems out of the ordinary before it becomes a real problem if you do this.