I have a couple of questions ?
First, what do the ants look like ? Big black ones, smaller red ones, or tiny bitty little red ones ?
Second, Are you parked at a permanent site ? If the answer to that is Yes, then the ants are in the ground outside the camper and just the worker ants are coming in to eat and take the food back home. In that case Terro works the best because the ants take it back to the nest and eventually it kills the queen. Spraying for that type of ant does no good. You are just killing the workers. You have to kill the queen and Terro works good for that but, it takes a little time to work.