Work place?

One manager and her istant inside our department at the bank constantly makes it look like my area is making mistakes and it is so obvious. Yet they try to pretend to be our friends. I am confused, how can they be so quick and happy to point out others mistakes? They are best buddies and are almost exactly alike in their condescending personalities and me me attitudes. I decided to only speak with them if I absolutely have to and that seems to work fine so far. Any other suggestions?