Who is his favorite super hero? Tell the boy that Spiderman and Batman always take naps so they can be ready for action at any time of the day or night.
In my experience not many children of 5 yrs of age need a sleep during the day, so this is probably why he isnt having one! Is the pre school pressing the issue? If so why?????
Make it out to be a game. Tell him, if you go to sleep you wake in The north pole filled with sweets or say lets see who can pretend to be asleep the longest. Hopefully he'll really fall asleep
As with bedtime, it's all about routine. At my son's preschool, they sit with each kid and rub their back until they fall asleep. Nap time happens right after lunch. The kids eat, go potty, wash their hands, and get out their nap time stuff. They can bring a stuffed animal, blanket, and pillow for nap time (that's the only time they get to bring out their stuffed animal) so nap time is kind of a treat.
In the nursery the children stop having naps when they no longer want them, this is usually at 3 yrs old. He's probably too old and no longer needs a nap, theres too much fun to be had.