Ken Pawlowski, a veterinarian at Insight Veterinary Wellness Center in El Dorado Hills, California, says, “Leave the carrier out for a couple of days in advance with the door open.” The crate becomes like the irresistible empty cardboard box, Pawlowski says. “Remove the carrier the night before, then put it back out the morning of the trip so it becomes new again. They will likely go and sit in there. Then just close the door.” —Maisy Fernandez