There's 3 things the buggers are looking for.
Shelter that is close to both.
Try to get an idea where they are coming from and going to. There's a chance they are making a home somewhere on the rv where there is a leak. Alot of times they're active at night and you can see where they are going. Feel around the paneling or exterior for a soft spot and you'll find the leak area and their home.
May not always be the case but I battled them in an old tag along I had. I took away the food and water and literally watched them move out in the middle of the night to a wood pile in my yard 100 feet away.
Another time when we were looking at purchasing a Cedar Creek I observed ants all over the slides interior. I had the salesman put the slides out and found every corner of the exterior on the slide to be wet, punky, and rotted floor. The coach was only 4 years old.
I'm not trying to scare folks, I'm just saying it may be an indication.
*Current: 2005 Ford F350 Crew Cab Dually 6.0 diesel 4x4*
*Retired: 1987 F350 Crew Cab Dually 6.9 turbo diesel
2007 Forest River WildCat 32QBBS