So I'm picking up a few full grown chickens this week but I don't have a clue as to how to get them from the farm to my house. I've built a chicken tractor for quarantine time so I could load that into the back of my truck but I don't know if that would give them too much space (and no seat belts...). I don't have a dog crate, which would probably be best. Cardboard box with holes??? How much space do 4 chickens need for transport? Thanks!