Some good advice so far, but let me add to it as a 15 plus year full time RVer.
o Before you start spraying or whatever inside, follow the track as best you can to the source. The track is endless so killing the ones inside will do no good - and cause you to lose the tracking to the source. The idea is to kill the colony and queen.
o As noted, "anything" that touches the ground will become a source of ants. I have a habit of leaving my awning puller leaning against the rig - but that once became a source. The main source into my rig has been the water hose - or other hookups such as sewer and electric. Have never had an ant come in via my tires.
o Some sprinkle household cleanser such as Comet around tires and stabilizers. I have never found that to work. I once took photos of ants streaming over cleanser around tires.
o The very best I have found as to keeping them away from entry points such as tires is Diatomaceous Earth. I have "never" witnessed an ant make it across DE. It is now illegal in certain places but if you can find some and are OK with using it, it works. The problem, I understand, is breathing the powder - whereas otherwise it is harmless to pets and such.
o Finally, the best all round treatment inside the rig is the
TERRO baits. The bait housing is transparent so you can see what is going on. The liquid inside is made from borax - so not harmful to people or pets. However, it is deadly to ants - plus it takes awhile for it to take effect. During this time, the worker ants carry the borax mixtrue back to the colony and the queen.
The first time I used them I at first didn't think it was working. Once they found the bait container, it quickly became full of ants - millions of them. But they didn't seem to be dying, just enjoying the meal. However, a closer look noted that they were leaving after a snack back along the ant trail. The next AM all the ants were gone from the trap other than a few dead ones. And that trail stopped coming in.
Hope this helps and that you get rid of the ants - and hope that you never get mice or rats. That can become real grief.
