Do I have a right of refusal for an Housing Urban Development inspection?

I live in Nebraska and got a letter from my apartment complex stating that the Housing Urban Development is doing inspections and my apartment may be selected to be inspected. It seems I get this letter every other month or so. I am wondering what my rights are as far as not letting them in to my apartment. I am not on any public assistance whatsoever and don't believe if I am not that I should have to allow them to enter my apartment. I pay my rent every month in full and on time and would think that these people should only have the right to do this only if I was on some sort of public assistance. Also, is this inspection so the apartment complex can be certified or keep their section 8 status?