This isn't my story but I don't think the person it happened to will mind me retelling it. Names have been changed to protect the innocent idiots. Any other inaccuracies, exaggerations or misrememberings are down to me.
***
Bob had gone to buy some point of lay pullets from Dave. After they'd agreed a price, Bob asked if he could also buy some of the foldout cardboard poultry crates Dave had, to safely transport the birds back to the farm.
"Oh, you don't need those" said Dave. "Just put them all in the back of the van and as soon as you start driving, the movement will send them to sleep!"
Bob was skeptical but they'd already haggled over the price and how many chickens he was buying, and he really couldn't be bothered arguing any more. They loaded the pullets into the back of Bob's van, he set off and sure enough - the motion of the moving van soon had all the birds fast asleep.
They were making great progress, coasting down the motorway, when the traffic started to slow. Soon they were stopped completely, gridlock for miles up ahead and no sign of anyone going anywhere soon.
Bob's sitting in his van, waiting for the traffic to get going again, when he hears it -
Braaaaap
Oh no.
Braaaaaaaaap bokbokbok
They're waking up.
The front of the van isn't fully closed off from the back and soon a curious beak pokes through from somewhere behind the driver's seat. He pushes it back but another appears, then another...
There's too many of them! The front of the van starts to fill with chickens. They're on the seats, in Bob's lap, up on the dashboard and down in the foot wells. He can barely see through the windscreen. All the people in the surrounding vehicles are watching now, staring in disbelief or laughing hysterically, but never mind them - how's he going to drive like this when the traffic starts moving again?