Is mozarella and ricotta cheese vegetarian-friendly?

So I recently found out about animal rennet and how it is added to cheese as an "enzyme". I now buy tillamook cheddar cheese, which contains no animal rennet. I was going to make italian stuffed shells with ricotta and mozarella cheese, but i wanted to know what enzymes are in these cheeses? Are there some brands that do not use animal rennet, which is stomach lining, as an enzyme? I think I read somewhere that ricotta cheese doesn't have any, but I am not sure. Tillamook doesn't make mozarella cheese, so I couldn't buy it.