when we got our 17 it had a light infestation, the previous owner used lots and lots of talcum powder but didnt really do much as they were already in the van, we used ant rid,(the sticky liquid in the small bottle) around the van,also found a 4 pack of bait stations at woolies which we put in places with lots of ant movement, and also lots of ant sand around drop jacks, wheels, (anything that was in contact with ground)
end result is a van free of ants, just need to keep up the outside treatment to stop them getting near the van.
1 battle won but the war is just beggining