Sometimes I wonder about people on here. There was a person asking about transporting some very young pullets for a 13 hour trip. They planned to run the car's AC so they wouldn't overheat, and not put too many per cage. Watermelon slices were considered for hydration, so it wouldn't spill making a mess. I suggested smallish boxes, with plenty of air holes at various levels, and on all sides of the box. Watermelon might work, but it would be better to stop every 4 - 6 hours, and offer them some water. When transporting, I use a couple cups that have been cut down, and bottled water. That way at the end of the trip, I can toss the cups into the garbage.
I was informed that transporting chickens in boxes will kill them, because there is not enough air flow, even with holes cut into it. Dog crates with plenty of room are best.
The first time I transported chickens was a trio I got. I learned a LOT about transporting chickens on that trip. When I met up with the person I was buying the chickens from, he had brought them from Alabama to Florida in cardboard boxes. It was winter, so AC was not an issue. The boxes were not very tall, so the chickens could not stand, and there was not a lot of excess room for them to move. When I saw that, I was a bit taken aback. I got my chickens, and loaded them into a nice big dog crate, in the back of my SUV.
At first, getting out of the parking lot, turning on to the road, then stopping at the light, then turning again, the chickens had room to slide around. NOT good. Sliding chickens can get hurt. I went real slow when stopping, turning, or accelerating to keep them from sliding around. After I got on the interstate and had traveled a bit of distance at a steady pace, they laid down. They stayed laying down the rest of the trip home. They didn't need all that extra height the crate provided. I understood the merits of a well ventilated cardboard box that was suited to their size when laying down, without room for them to slide around in. When I say well ventilated, I don't mean cut a couple tiny holes in each side. I put several rows of fairly good sized holes, not just at the top, but in the middle and towards the bottom on all sides, so they don't get too hot. I've never lost one yet.