Sometimes defeated enemies won't disappear, but instead, they'll just stand still and seem intact at where they're supposed to fall.
Thank you for pointing this out. Fortunately that's a bug we already know and we also know how to fix it :)
(in-depth stuff: it's because the enemies get a point to walk if the sun rises, but our world build algorithm is destroying the path to this particular point, so they hang around and shaking their bodies :P )