Strange Habit

Ivy has this strange habit every night and nap time. When she is being tucked in she insists on having a book to cuddle...like most kids have a stuffed animal. Even tonight, when she fell asleep on the way home from my parents, I carried her up and as I was laying her down she goes "book." So I have to tuck one under her arm. I have tried to sneak out without doing it and she has a fit. Some nights it is a book and a stuffed animal, but she can sleep without the animal. This has been going on for quite awhile now...weird.