If you’re going away for a while, Dr. Michael Fox suggests
you send your cat a "smell letter" to comfort him when he
doesn’t have you and your familiar scent around. To make it,
take a piece of paper you’ve rubbed on your forehead, hands,
arms, and lightly under your armpits, and mail it to where
he’s staying.
What should this "smell letter" say? It depends on whether
your cat can read.