What are the different subtypes of hitchhikers, cooties and fleas?

Attribute	Description
	A box without a permanent home, hopping from box to box, hitching rides from passing letterboxers.
	Why go out and find a box when you can plant one on other people? That’s what a cootie is for—hiding on other letterboxers, or at least among their possessions.
	Can’t decide between a hitchhiker or a cootie? A flea combines the best of both worlds! Hide it in a box or on letterboxer, and you can’t go wrong!