I have a 2000 Ford F-150 XLT 5.4L and I have air lift airbags in the rear. I fill them up to 50-55psi?

I put about 3,360lbs-3,800lbs in the bed sometimes. But very very little and very short distances. Just a question when ever the load is loaded the airbags squash down. How do they do that? Like where does the air go? They turn small. And when the load is off they go back. I'not just afraid they will pop or something.

Air compresses.
It's water that doesn't…