We would like to think that your subscribers like your campaigns so much that they feel urged to open them once and then come back to check them again.
But if you are certain that this is not the case, then there is always a possibility that many of your recipients might be using a "Preview Panel" option in their email accounts (this is a common option in various email service providers). When using the preview panel option, every time your recipient's mouse scrolls over your campaign newsletter sitting in their inbox, the campaign's images are downloaded for the preview and this is recorded as a Campaign Open in our platform.
No need to get alarmed, though. These "opens" are only recorded in Total Opens but not included in Unique Opens, so you still have a great and viable metric to check your campaign's performance.