How does the owl post work and other mysteries in Harry Potter

Some details of Harry Potter remain a mystery to fans such as the owl post !

Here's what we know of it : every day the owls deliver parcels and letters and you can send something back the same way. However the system relies solely on owls being able to locate the wizards to whom the mail is addressed...  This also applies to Sirius Black when he goes into hiding but then if an owl can find him why isn't the Ministry of magic able to do so as well ? 

One might suggest that the Ministry is not very efficient as a partial but very likely explanation !

From Metro.com

Another mystery is Scabbers. Ron brings him from his first year to Hogwarts when it's clearly mentioned his the admission letter that rats are not animals students can bring along as there could be complaints about having a rodent around in the dorms.... Maybe Fred 's and George's mischievous tricks and jokes are so numerous that Scabbers seems something reasonable from a Weasley and the school let it go !

Read out some more Harry Potter mysteries in What culture's and ScreenRant articles !

Cover picture from Mirror