I'm going nuts and losing the battle!!!

Hi All

Can anyone help? I'm going nuts and losing the battle.

We park the BT out in the open here at the Batchelor Outdoor Education Unit and the meat ants have found their way up the wheels and then up the sink and basin.
Put the plugs in and replaced the stockings on the outlets, this stopped the meat ants.
But two days later I looked up and saw the little tiny brown ants walking across the ceiling and collecting around the CD/DVD player, then moving up and along towards the ensuite but disappearing at the top of the shower door. I then went outside the van and there the little devils were, marching up the front of the van and obviously finding a miniscule gap in the sheeting.
Can't find where they are going and have a mindless fear that they have taken up residence in the walls.
In recent years we discovered this same type of ant in the engine of the car and they were enjoying the taste of the wiring!!
Also noticed at the same time that even when the 4seasons hatch is closed I can see daylight and there is a buildup of red dust around the hatch and on the screens.
Hoping someone has an answer that will dissuade me using a shotgun inside the van!!
Prue