If you didn't cover the acorns with an inch or two of soil after snapping this photo, you might want to go ahead and do that. It'll add a layer of insulation against temperature swings, and it'll help keep the acorns from drying out too much.
Yep, they're covered and kept a bit higher up to hopefully deter any scavengers. Thanks for the tip though, because I was definitely doing some Google searching as I haven't planted any acorns on purpose before.