CMA vs LPN.. Who is the NURSE??

I work for a large company, we have everything from Office Assistants to RNs in our offices. I am an LPN and it bothers me that the CMAs in the office refer to themselfs as NURSES. They have often said that they dont know why I am there because they can do everything that I can do. This is not the case. They do everything I do but its not in their scope of practice and I made it very clear that I will not assist them in doing things that are not in that scope. I refer them to the supervising nurse and she assists them. I just dont like the fact that I went to school, worked hard, sweated through state boards and got my license and they call themself nurses. Am I right for feeling this way?