Why are there ants on my bed?

So I was laying on my bed using my laptop this morning when I notice an ant crawling around on the screen. No big deal, I kill it and throw it away; a little while later I see another, go through the same cycle, don't think anything of it. But after it happens the third, and fourth times I look on my bed (stupid of me not to notice this sooner I guess) and see around six ants crawling around.I freaked out because I absolutely detest bugs of any sort. I just went back in my room and investigated; I still saw ants! What should I do? Where are they coming from? I think there may be some old candy wrappers behind my bed; could that have something to do with it? There is also a glass that had coke in it on the window ledge right by my bed... but I looked in there and didn't see any of them in the glass. I'm scared to pull my bed back from the wall, because I'm thinking there might be a lot of them due to the candy wrappers. However, I've never had a problem with them crawling on my bed before...Thanks