Paricle light problem

Hey guys, i have a little question that i can't figure out for two days now. I am new to unity and just have a few experience so forgive me =D

I am playing a little bit around with Particles. I watched a lot of video tutorials and figured out how to get them in shape and everything.

But my problem is that this particles seem to be a light source. You can see them even if it is completely dark. That is really bad if you are trying to create smoke and things like that. I am creating a game were darkness is important and the only light sources should be my flashlight and a few other things so it very bad that the particles acting like a light source.

Can any body how i can change that? Is there a way?

Thank you, Matt

P.S: Sorry for my bad english. English isnt my native language^^