You have a warm place to live with food and water...it's a perfect home and they can squeeze thru the tiniest cracks. Best bet is to keep available food and water to a minimum.
Bug bombs will generally get rid of them if you don't mind using them.
One kind of ironic thing would be to go north to freezing temps and let the rig go cold (stay in a hotel or something). They don't survive freezing weather. The only reason northern buildings have them is the buildings are heated, so they can survive.