I think a neat addition would be a sort of false-fast travel. By letting the player sleep anywhere (perhaps with a sleeping bag item), a monster could carry them away to their den. The player would have some control over their destination by choosing what monsters are nearby when they sleep, but there's a risk of ending up in someone else's den instead. So more fast travel locations than just camps, but it doesn't always work the way you want. For example, sleeping near lechos on the small mountain left of spawn might take you to the lecho cave nest to the right of spawn. Or you might end up in a furloin den.