Slugs, snails, flea beetles and larvae or small green worms all make holes in leaves. The beast may be hidden in the soil or under a leaf of just one plant and has not yet rambled over to attack the other. I suggest you go out at night with a flashlight to see who is eating the foliage. You can hand pick the worms and set out slug and snail bait. Don't worry - your Datura is unlikely to die from the attack but some detective work will help salvage the appearance. Enjoy those fragrant daturas. Keep growing, Marianne Binetti