How long after I get ants in my room until more critters come in?

Alright...So I had some chips and accidentally dropped some crumbs on the ground and didn't realize it. After a few days, I noticed a group of ants right below my feet. I'm currently stationed Iraq and they warn us about not having too much food in your room to keep away scorpions and stuff like that. I don't have much to get these things away and I've tried soap and water once which kept em away most of the day it seems but they jut keep coming back in small groups. I'm wanting to know if I can get rid of them permanently, and how to do it, and/or how long it may take until my critters start coming into my chu.