If your goucho is like mine it's pretty easy to get it appart where you can see the floor. The water tank may be under it as well. Ours has drawers under it.
Pull the seating off. should be a few screws holding the plywood down. after you get the screws loose the plywood deck should come right up. If there is not enough room to get your fingers in around the ply wood, slide a drawer out and you can push up on the deck from below. Get a screw driver out and start pushing it into the floor and see if you find any soft spots. pay close attentions to the area where it meets the shell. That's the place that usualy get's wet first.
While the belly pan does a great job in preventing water from getting to the wood and insulation from below, if water gets at the wood from above it causes a big problem. The air can't circulate and the water just sits there.
Once the wood dries out the ants will leave. That's why I am concerned that you have some wet flooring.
1959 22' Caravanner
1988 R20 454 Suburban.