A state trooper

A state trooper is driving down the highway when he sees a truck driver pull over, walk to the side of the truck with a tire jack, bang on the side of the truck a few times, and then drive away.

A couple of miles down the road the driver does the same thing.

A few more miles, same thing. The trooper pulls the truck over and asks the driver to explain.

The driver says, “Well, the load limit is ten tons, and I’m carrying fifteen tons of parakeets, so I’ve got to keep some of them flying around.”