Feral cat in 5er

There's no need to trap the cat unless you want to give it to your local rescue group or something. Just make your rv an undesirable nest so the cat will find another home.

First thing to try: noise. Go in the rv and jump up and down, bash some pots and pans, turn on the water, etc. Make sure there is nothing OUTSIDE the rv that would make the cat hesitant to exit. No humans watching, no dogs, etc. Dawn or dusk would be the best time, because that's when cats are awake.

Then make it unappealing to come back. Cats don't like strong plant smells. Anything menthol, mint, lemon, eucalyptus, lavender etc., scented repels them. I used some mint-based wasp spray just today as a repellant. Lemon Pledge might also be good.

Of course, if there are kittens that's different. If you scare the mom too badly she will abandon them. If you scare or annoy her just a little bit, for several days in a row, she might move them. That would be ideal. Jump on the floors twice a day for 3-4 days. Noon is a good time because that is bedtime for cats.

If you end up with a litter of kittens and no mom, keep them very warm and call cat rescue. They will find someone to bottle feed them and find good homes for them. The kittens will be tame if raised by humans.

When using a Live Trap approved by the L.A. City Animal Services for trapping feral cats, I used the scraps from making fried chicken wings. The smell of those tips drive the cans nuts.

I disagree. Get yourself a smoker as the beekeepers use. He will exit quickly.

If that cat is/was in there for more than 1 day, you need to catch it and then check it to see what sex it is. If female....check it if appears to have given birth to kittens. {enlarged rear end, nipples extended, so on and so forth}. Most feral cats go into a hiding spot for birthing.
You don't want to leave 5 or 6 kittens in there to die, not just for humane reasons, but also for the smell.

Food and water. Animals are smarter than we think....Dennis

it went in there for a reason,either food or maternal happenings.

There must be a hole or a loose unscrewed down area on the coreplast. The trap idea will work. It might be eating mice in your unit tho

Cats are a lot like mice! They can squeeze through just about any size or shape hole, and can ball up or stretch out and fit any space.

The live trap with some smelly food is your best bet to catch it. I will get hungry. Hopefully, it knows how to get out on it's own and won't die inside the underbelly.

live trap with food.

If you can find where it goes in and out, put the trap nearby.

I'm guessing it got in around one of the larger penetrations through the belly covering.