I was just wondering if there was a way to make an NPC lie down in a bed. Are there any mods that do this? I'd like to take a look at them and see how it's done.

Clothiers of Vvardenfell - go to the tavern in Caldera I think it's called the Wailing Wench - look in the bedrooms upstairs - there's two different animations used - they are just NPC's with sleeping animations added and placed on the bed - IIRC - they should be just standing on the bed in the CS - when the game begins they collapse into the sleeping animation.

There is also one of the traders of Cyrano's Traveling Merchants 2.2 who can get caught sleeping at night.

I'll have a look at those. Thanks!

RX31's animation resources have sleeping animations. Also, the http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=7545 mod has some of the thieves in the underground lair laying in their beds on their backs and on their stomachs.