Sounds like my kittens.. ran out of the carrier straight under the chair / behind the fridge when we came back from vet...
I wonder when is most frightening to them..? When they cower and trembles quietly.. or when they mew loudly?
Speaking of carrying cat/kitten around, do you think those calming remedies work? (I saw some liquid type / spray pheromone thingy to calm down your cats.. wondered if it works..)